Some things are already timed.
Some areas block teleporting.
In tabletop you ask the DM about taking a SR or a LR, they can consider the situation ( like the party was all crit on every attack and will have a tpk if they continue).

Some timed fights and quests are a good idea. But not for the whole game, let players play how they want.
And I hope we get maps where we can't rest or teleport out of, nice test of strategy and resource management. But I don't want that for the whole game. The Hags lair is a simple version of that in act 1 (encounters will be more challenging in act 2+ and with higher difficulty settings).