So, If I understood correctly, Foundry USA can remove block that they mined. There might be a case when they mine two blocks in a row and they'll be able to remove both blocks from the blockchain, right?
No, you didn't understand it correctly. It doesn't matter who has mined the blocks and it's not that a mining pool can remove the blocks mined by themselves.
Keep in mind that the winning chain is always the one that has the most work. To remove a block from the blockchain, the dishonest mining pool have to create a new chain that doesn't have that block and has the most work.
Read
my previous post, please.