My guess would be that the B92s start getting withdrawn so more B23s can be delivered, before any service increases happen.
Although it would be nice to have the Beckton branch get it’s 12tph back soon. We’ve suffered far too long with just 6tph
There are 12 new B23 (from memory) delivered, each one back in service replaces 2 or 3 older trains (depending on if replacing a 2 unit or 3 unit service)
If 3 go back in service initially (and let's hope soon climbs to 4 or 5) then covers the gaps, A few will need to do staff re-familiarisation for a while (not in public service). Then later be used for staff that still need to be trained up.
Once there is about 4 or 5 units in service, can start to withdraw the older trains to make space for more new ones to be delivered. Effectively 3 old ones can be withdrawn as every new one is delivered and commissioned.
I understand it takes about 7 or 8 days round trip for the specialist road transporters to deliver a unit from northern Spain to Beckton (roughly a day to load, about 850 miles by main road, day to unload, return 850 miles empty), without knowing lorry driver breaks etc. I would guess delivery rate is maximum 3 units every month. And there are 42 of 54 units still to be delivered. My guess is will take until about November 2027 for all units.