Like it or not, I think the trend towards the "classics" is a nice change. Granted Justin, Wade, LBJ, etc. may not subscribe to a majority of the CM "rules" (guidelines are probably more accurate), but I think it's a pleasant shift. I would rather see interesting suits, ties, and shoes than oversized t-shirts, jeans, and sneakers. Additionally, the dressier popularity does impact designers (e.g., RL) and allows us (who cannot bespoke everything) access to them. However, going too far definitely has its negatives (e.g., popularity of wingtips results in an Aldo explosion), but I think it's part of the cycle.
Regarding Mr Grant, yes, he dressed well, and was admired for looking smart during his time. He wore nicely cut suits but was still influeced by the trends (e.g., higher waist line, more voluminous pants). Comparisons across generations are more for conversations rather than anything. We all do it, comparing someone contemporary to a legend of the past (Steve Young vs. Joe Montana), and at most it creates stimulating debates.