Nah, you're good - the pool shouldn't have any issues with coinjoins anyway, but any that are there will soon be fixed - or coinjoins will be streamlined to work more efficiently. Even if all pools adopted a policy of not relaying or confirming transactions from coinjoined utxos the damage would be catastrophic and some sort of fall out event would probably lead to a split. It's in no miners interest to have a repeat of the blocksize wars.