Not when they get fed up with standing to Ipswich. The train with plenty of empty seats then starts to look a lot more comfortable. The railway has been changing since the '60s:
First the SOs all became TSOs
2nd class compartments were disappearing fast on MKIIs and were all gone on MKIIIs
First class compartments are very rare on MKIV and post stock
End doors will become rare outside stock dedicated to journeys where stops average about 30mins or more apart or low density branch-line stoppers*
*See TPE 185s & 350s
With Norwich commuters calling for a 90minute run to London, the line will have average journey times no longer than many other London outer suburban routes. It may be unfortunate for Norwich that there's nowhere to go beyond there and traffic beyond Ipswich is hardly brisk all day but that's the way it is. If it's '80s style rolling stock that they want then better be careful of what they wish for in journey time reduction.
Why would they be standing to Ipswich if the route gets 26m stock in nine-car formations (I think Liverpool Street platforms are around the 240m mark, so 9x26m should fit and I can't see any serious infrastructure impediments to 26m stock on the line), seating 650 people or so, assuming you order something like a Class 801? A 12-car 387 seats about 670-680, so hardly an earth-shattering difference.
We know for a fact that many of TPE's new trains will have end doors - they may live to regret it, but there we are. The other new trains may well do too.
Norwich is not my idea of outer-suburban, which I would put at the one-hour mark, so Colchester, Cambridge, Peterborough (on an emu) range, if we stick to East Anglia.
While a limited number of people may well commute Norwich-London, there are plenty of studies which put 90 minutes at the outer limit of what is considered a reasonably practical/tolerable daily commute. And the couple of 90-minute services a day that the new franchise is supposed to provide won't change that.
If we adopt the approach you and southern 442 advocate, then SWT should presumably have just ordered lots more 450s instead of those frivolous 444s with their fancy end doors, GWR should be using 387s to Bristol and Cardiff....:roll: