A little confusing but I have a problem with it.
Being "timed out" on a tournament while you are playing may happen early in a round,. It just isn't announced to the player until the last shot of the round being played. A need for things to be streamlined and not overtax systems even more necessitates that WGT check it a minimal number of times a round. They do it once, just prior to the end of the round.
Filling in an arbitrary score without playing the hole in any stroke play tournament is clearly not legitimate. Allowing a player who is going to miss a deadline to fill in a par is totally unfair to everyone else in the tourney who took bogey or worse on the hole. If your abitrary filled-in score were the max allowed by the game for a hole then your proposal would make more sense since you could not have done any worse on that last hole.
It is the individual player's responsibility to check on and meet the deadlines as they are set. An argument might be made for opening a longer "window of opportunity" when setting how thing work, For multiple round tournaments I'd personally like to see the date of each round set and announced as part of the tourney set-up. Then the player knows and can decide if they can play all rounds within those time frames.