MEP - forcing out a member that severed the relationship with the sponsor?

I've got a PEO MEP.  One of the members terminated their service agreement with the PEO effective 1/31/24.  Is there some kind of timeframe or requirement that their assets have to leave the MEP?

In case it matters:
> There is a SHNEC deposited after we calculate it EOY.
> They have not yet made arrangements for their portion to be spun off (no TPA or asset custodian chosen, etc.).
> They have also not made arrangements for anyone to administer their spin off going forward, so I told them that they have to cease deferrals at least temporarily (because there is nowhere to submit them).  I'm not 100% sure that is correct; is there a better option?  I'm presuming this won't affect SH status since they will still all get 3% of full year comp when someone does the annual 2024 administration.

Obviously, the PEO sponsoring the MEP would like them gone as soon as the product platform can get them out.

Thanks.