Umm, of course not??
Wha--?
It's very simple, as no money has changed hands.
The only expense had been on pubs for the beta's development and launch, which is subsidised by the game's own development, and the remainder being marketing costs anyway.
well obviously devs/publishers wouldn't lock betas behind pre orders if they wanted people to play the beta without buying it. What other reason would there be?
To artificially boost pre orders that's all. It's advertising.
Pre order locked betas are just advertising exercises, they're made to sell games.
Pubs lose nothing if you pre order and cancel.
Think of it logically OP, say for example you pre order a game and then the reviews come in before release and it's rubbish, and so you decide to cancel your pre order before it releases.
Is that morally wrong? Of course it clearly isn't.
And there is very little difference between your described scenario and mine.
Both transactionally have 1 pre order that is then cancelled between you and a retailer, no money has changed hands, and no obligation is outstanding.