This question doesn't really have an answer, or at least, not one. Luther is quite content to maintain the term Mass for his vision of the evangelical Eucharist/communion-containing ceremony (see Deutsche Messe, 1526), within his/what will become the Lutheran understanding of the sacrament and, of course, in German. The Reformed protestants (Calvinists et al) and early Anabaptists use Lord's Supper or Christ's Supper from an early date, in concordance with those two (very different!) general understandings of what a religious service should look like and the theology of communion.

A good illustration of rhetorical divergence can be seen in how Luther and Calvin consider the traditional/Catholic Mass. Luther describe it as "the abuse of the Mass," suggesting an institution that has been corrupted and needs fixing. On the other hand, Calvin in his Institutes writes of "the abomination of the Mass." He directly addresses the labeling, explaining that the term Mass probably denotes specifically the idea of pagan sacrifice and can only refer to the Catholic belief that it is the actual body and blood of Christ. Supper on the other hand is biblical.