And then what. Would other pools just stand there and take it or would they put a filter in that looks for foundry in the Coinbase tag and invalidate those blocks.
Practically speaking, they wouldn't have done this beforehand, so when Foundry mines two blocks on a row and creates a longer chain, their full node software would automatically switch to that. At least, I'm not aware of a mining pool which has altered their node software for that particular case; makes no sense.
AntPool and Via and F2 would crush Foundry out of existence if they really tried that.
Followed by their reputation. No sane miner would mine on a pool that wants to crush other mining pools out of revenge.
On the one hand, replacing a valid block for profit is bad, but on the other hand, ignoring the longest chain to keep mining a shorter chain is also bad. I'm not sure yet which is the worst.
Ignoring the longest chain for the sake of ethics is one of the most destructive ideas. Bitcoin is based in a game theory, and it shall be based in this forever.