I noticed when you run a timelock from Zion on coinb.in it notifies you that this is a RBF transaction.
I'm not sure Ive ever noticed this with other multisig timelocks.
Does this mean you have to worry they could RBF your multisig and make it worthless?
No, it just means they can increase the tx fee in case things get more expensive by the time the timelock releases. That way you won't have a tx get stuck in limbo and never confirm.