Think blindfolded 1400 players, which is what this effectively is, would make illegal moves.
But even if it doesn't play like human 1400 players, if it can get to a 1400 elo while resigning games it makes illegal moves on, that seems 1400 level to me. And i bet that some 1400s do occasionally make illegal moves (missing pins) while playing otb
This isn't really an apt metaphor. Firstly because higher level blindfolded players, when trained to play with a blindfold, also virtually never make mistakes. Secondly because a computer has permanent concrete state management (compared to humans) and can, without error, keep a perfect representation of a chess if it chooses to do so.
Personally I think the illegal moves are irreverent, the fact that it doesn't play exactly like a typical 1400 doesn't mean it can't have a 1400 rating. Rating is purely determined by wins and losses against opponents, it doesn't matter if you lose a game by checkmate, resignation, or playing an illegal move.
That's not to say ChatGPT can play at 1400, just that that playing in an odd way doesn't determine its rating.
No it's not, we're not ignoring losses or illegal moves at all, they are counted as losses and that's how you arrive at 1400.
It's a (theoretically) 1400 player which plays significantly better then 1400 when it knows the lines, but makes bad or illegal moves when it doesn't, and that play averages out to be around your typical 1400 player. Functionally is just what a 1400 player already is, but with higher extremes and lower lows.