Did BC Game allow cross chain swaps before or they only provided swaps on a same blockchain?
There is no on-chain swap on bc.game. In other words, when you swap your coins/tokens on bc.game, no real transaction is made and it's only your tokens/coins balances that change.
It's more likely that they only provide same blockchain swaps as cross chain swaps are more risky with deployment of bridges. This pause (maybe temporarily or permanently) of swap on TON blockchain can come from its small ecosystem than other blockchains.
No.
As I said, when you swap your tokens/coins on bc.game, no real transaction is made and that means that nothing needs to be recorded on the the blockchains at all.
I just checked the swap page on bc.game. TON isn't available now while I can see many many other coins/tokens there.