Certainly, Francis had been a key figure in the liturgical reforms and the suppression of the Vetus Ordo including his promulgation of Custodes traditionis. It is not necessarily true that this involves the suppression of the Latin language in the sacred liturgy, but it is mostly true, since the Vatican II reforms involve a much greater implementation of vernacular languages.

So one of the sad ironies of his passing, from the announcement of his death, to the inscription on his tomb, has been the usage of Latin for those liturgical proceedings. The Holy Father was never a huge fan of using Latin himself; in fact all the encyclicals and other documents were authored primarily in Spanish or Italian, and only translated to Latin after the fact. Some endured long, long delays before these Latin translations were pushed to the website.

So yes, perhaps there is some spite involved, in using an approximation of the "Times New Roman" font and really awful kerning, for a Latin funereal inscription for a guy who was more or less Public Enemy #1 of the language itself.

I am also curious to know the value or rarity of the stone itself, as it is used in the inscribed part of the slab. If they decide to replace it in the near future, will this incur a great cost or loss of precious stone?

Whatever the cause, perhaps a fitting conclusion to the false humility of a pauperized papacy.