One of the above posts reminded me that the tender potentially didn't even cover a like-for-like Networker replacement did it let alone the 376s and 707s? I know it was for a range of trains but the low end was, well, pretty low. And at the high end not huge to replace everything?
I think the 376s and 707s will stay in addition to a Networker replacement. The treasury won't want to underwrite wholesale replacement and the days of cheap finance in the 2010s are long gone when we saw wholesale replacements elsewhere.
SE Metro never seems to get much luck. The Networker orders in the 1990s were cut back due to a recession back then. Now we're in a time of sluggish economy and high borrowing costs and that could well hamper any order.