Well, I cannot say for sure, but physics dictate that after 24.6 years (based on the half-life of Tritium at 12.3 years) the T100 would have 1/4 its activity, or the equivalent of T25.Fantastic review!
I wonder if you can say the T100 tritium would stay brighter longer (over 25 years) than the T25. Certainly would be another good reason to go T100.
So, yes. I expect the T100 tubes to stay brighter longer.