They exist in the current BattleTech timeline, so it is coming.
One thing that irritates me to no end: The Inner Sphere has, at this point, had more then 50 years of access to clan technology. Why the HELL can they not manage to dumb-copy clan technology at this point that they've had more then 50 years of access to? Everything in the inner sphere should be rocking clan equipment (except for maybe the most advanced clan things like ATMs and iATMs)
50 years?
The Helm Memory Core was discovered 34 years before the FedCom Civil War started. The Clan invasion was only over for, what, a decade? The IS states were working with mostly shitty half-baked R&D and manufacturing. Yet from 3052-67 they managed to reverse-engineer or parallel develop LAMS, U/AC 2/5/20, ERM & SLas, S-SRM4/6, LB 2/5/20-X ACs, TComps, and Light TAG, among others.
That's in addition to the small mountain of tech advancements which were their independent and original developments. So in the 10-15 years after the Clan invasion had ended, the IS replicated pretty much all of the major techs that the clans had up on them.
It's hardly fair to talk about stuff like ATMs, since the Coyotes only started introducing those well
after the Invasion/into the Civil War era. Might as well wonder why the clans didn't have HGRs or RACs three or four years after they were prototyped.