Not much can be inferred, I am afraid, from the fact that Messmer's name reappeared on the SFB site: a number of other dancers who we know will not be dancing next season reappeared as well. That may be simply a publicity move before the Summer tour anticipating that many European ballet goers would be visiting the SFB site to learn more about the company.
Sadly, I have to agree. I’ll believe Messmer will be back when I actually see her on WMOH stage. By contrast, Froustey was on the roster as soon as the 2015 roster was put out, so her return was more or less a sure thing from the start.