Another problem with the change is the stigma associated with the term
Training Mode. (Apologies if this issue has already been raised.)
As this discussion shows, plenty of people are good at games certain games (and have a high ELO to prove it) but would still like to play (competitively, but) without time pressure, for any number of reasons.
But none of these people want to feel like they're being treated like children or newbies and — intentionally or not — the term
Training Mode implies either one or both of those.
My personal preference — for what it's worth — would be to bring back unlimited time games, only allowed between mutually-declared Friends (as before), for
Turn-Based games only (not as before, but then, it
never made sense for Real-Time games) and call it "Friend Mode'.
Since all turn-based games expire after 5 weeks if no one takes a turn (I'm looking at you, Vektorace!), no one will be eternally trapped in a game.
(Note to all the people saying that players should be more careful about their online friends: that's no answer. On other turn-based game sites, I've played against consistent, dependable and friendly players for years, only to find one day that they were no longer playing. I had to assume that they had died, and had been so inconsiderate as to not leave instructions to their loved ones to log in to the game site and let all their opponents know, as I'm sure you have all been careful to do.)