It would be foolish IMO not to make a type 20 at this point.
[Extremely simplistic viewpoint]
They have the rubber moulds and dimensions for the externals, the stock is close to the scar so they don't have to spend loads in R&D on making that, the charging handle is non reciprocating so no SCAR broken issues there (for GBB or NGRS), and ambi fire selector is again already designed.
They would need to make sure they can fit a gearbox in there or the MWS system, and the ambi mag release but thats about it. And official TM P-mags would just print money.