Note, here are the texts of canons 1184 and 1185:
§1. Unless they gave some signs of repentance before death, the following must be deprived of ecclesiastical funerals:
1/ notorious apostates, heretics, and schismatics;
2/ those who chose the cremation of their bodies for reasons contrary to Christian faith;
3/ other manifest sinners who cannot be granted ecclesiastical funerals without public scandal of the faithful.
§2. If any doubt occurs, the local ordinary is to be consulted, and his judgment must be followed.
Can. 1185 Any funeral Mass must also be denied a person who is excluded from ecclesiastical funerals.So canons 1184 and 1185 already settles the issue.
But just for further reference on Masonic associations, here is the declaration of the Vatican CDF issued on November 1983 by then Cardinal Ratzinger. Note that this declaration has been specifically approved by the then reigning Roman Pontiff, John Paul II. It is the latest statement by the Church to date. I quote partly, with emphasis:
Declaration on Masonic Associations
...Therefore the Church’s negative judgment in regard to Masonic association remains unchanged since their principles have always been considered irreconcilable with the doctrine of the Church and therefore membership in them remains forbidden. The faithful who enrol in Masonic associations are in a state of grave sin and may not receive Holy Communion.
It is not within the competence of local ecclesiastical authorities to give a judgment on the nature of Masonic associations which would imply a derogation from what has been decided above, and this in line with the Declaration of this Sacred Congregation issued on 17 February 1981..."
The aforementioned declaration thus follows:
Clarification concerning status of Catholics becoming Freemasons
On 19 July 1974 this Congregation wrote to some Episcopal Conferences a private letter concerning the interpretation of can 2335 of the Code of Canon Law which forbids Catholics, under the penalty of excommunication, to enroll in Masonic or other similar associations.
Since the said letter has become public and has given rise to erroneous and tendentious interpretations, this Congregation, without prejudice to the eventual norms of the new Code, issues the following confirmation and clarification:
1) the present canonical discipline remains in full force and has not been modified in any way;
2) consequently, neither the excommunication nor the other penalties envisaged have been abrogated;
3) what was said in the aforesaid letter as regards the interpretation to be given to the canon in question should be understood—as the Congregation intended—merely as a reminder of the general principles of interpretation of penal laws for the solution of the cases of individual persons which may be submitted to the judgment of ordinaries. It was not, however, the intention of the Congregation to permit Episcopal Conferences to issue public pronouncements by way of a judgment of a general character on the nature of Masonic associations, which would imply a derogation from the aforesaid norms.
Canon 2335 in the older version of the canon law reads as follows:
Persons joining associations of the Masonic sect or any others of the same kind which plot against the Church and legitimate civil authorities contract
The current and revised 1983 version however, removed the previous provision an replaced it with Canon 1374, as follows:
A person who joins an association which plots against the Church is to be punished with a just penalty; one who promotes or takes office in such an association is to be punished with an interdict.
Following the promulgation of the new Code, Cardinal Joseph Ratzinger, the (erstwhile) new Prefect of the Congregation for the Doctrine of the Faith, issued a new declaration:
(1) the new Canon 1374 has the same essential import as the old Canon 2335, and the fact that the "Masonic sect" is no longer explicitly named is irrelevant;
(2) the Church's negative judgment on Masonry remains unchanged, because the Masonic principles are irreconcilable with the Church's teaching ("earum principia semper iconciliabilia habita sunt cum Ecclesiae doctrina");
(3) Catholics who join the Masons are in the state of grave sin and may not receive Holy Communion; and
(4) no local ecclesiastical authority has competence to derogate from these judgments of the Sacred Congregation.
My further comment is that the rule on automatic excommunication of Freemasons seems to have been more open to situational considerations with the effect of the new canon law. To be more specific requires the explanation of a good canon lawyer. Secondly, I am of the opinion that there is no real issue with Mass being "denied" to Gov. Nantes. The prohibition was merely reiterated. There is nothing in the report that says it was even requested by the immediate family. Add the fact that Nantes is a "born-again Christian" -- specifically a Protestant who does not believe in the Holy Sacrifice of the Mass in the first place, and has already disassociated himself by choice from the Catholic Church.
May the soul of the late Gov. Rafael Nantes rest in peace. Amen.