Bugger. That's a pain. I still use forks (Easton EC90 SLX, 3T Rigida) which either won't take 25s or are deeply marginal, and my Engima has only just enough clearance at the back for 25mm tyres underneath the brake caliper.
Guess I'd better go hunting for old stock to stock up on.
Schwalbe Pro Ones and Conti GP 5000 TLs are both available in 23mm widths.