It would be stupid of IR to fight a fight they’d probably lose. The way FI is coming at them it’s not some chill full out. They gain nothing unless they win, which is unlikely considering the number of years FI has had to build up a retired memberbase of experience members.
If it’s just about fun, why wouldn’t FI declare (for fun) on Apex? They’d be more likely to accept, the battle would be closer, the stakes higher.