My predicition is that some of the following will end up in scrapyards in 2022:
43s
86s
91s
153s (non-PRM units)
313s
315s
317s
319s
321s
322s
365s
373s (the remaining unrefurbished units that were withdrawn before covid)
455s (only in small quanities however, with there being no sign of the 701s entering service anytime soon)
456s
458s (The 6 units converted from 460s)
465s (465/2s)
507s
508s
LU 1972 stock (the ex-Aldwych unit)
Metro Cammell Glasgow Subway units
All remaining slam door Mark 3s (apart from those on the Night Riviera and in preservation)
Some of these are more of a guess than others.
I guess you would need to install shoegear and a new transformer but it would be utterly pointless with 465s currently off lease. The best thing for the Renatus 321s is to try and extract the traction package and fit it on something else but we have far too many brand new OHLE units on order already with surplus 720s for both Greater Anglia and c2c, let alone the homeless 350/2 fleet.
It is a bit of a shame that the surplus 720s (and the corresponding slack in the 701 / 730 fleets) aren't suitable as a replacement fleet for the 318s and 320s in Glasgow.
Although a 5 coach 720 is only a couple metres longer than a pair of 318/320 (maybe also a pair of 334s) so in theory could probably be used in Scotland as replacements, assuming there will be no issues with that extra couple metres at stations.
There are not surplus 720s. Both GA and C2C will need the full fleets that they ordered.
It is noticeable that Northern haven't taken all the EMR 156s on offer. Those 156s have no obvious future use.
The 4 units Northern aren't taking from EMR are the 4 Angel owned ones. I wouldn't be surprised to see these 4 units end up as spare parts donors for Angel's other 156s at Heaton and Corkerhill, I doubt they'd be scrapped in 2022 though.
The fact that - other than accident damage - 91s were getting scrapped before 43s, says a lot about the staying power of the latter!
Or the value of the components?
I think it's much more likely reflective of that fact that Eversholt seem to be more realistic with their expectations of what stock will have a future use than Porterbrook and Angel. The 5 91s that were scrapped this year were all in poor condition, and of the many stored 91s at Doncaster Belmont those were the least likely to find any further work. Porterbrook (and in particular) Angel are frankly living in cloud cuckoo land if they seriously think there's any prospect of a future use for the vast majority of the 43s in varying states of decay in Ely and Long Marston. Many of the Ely powercars should really have been scrapped in 2020.