Pretty unlikely, given that NR has removed some (very lucrative) retail to make more space for waiting.
And it's pretty clear that those on the concourse aren't (unlike in airports) spending money in the shops, they're standing poised to run the second the platform appears.
Solving the problem (by some of the mechanisms, such as later reservation availability so you can reserve on an existing walk-up ticket from your phone before you head to the station or even on arrival there) would make people
more willing to spend money in retail.
I mentioned easyJet above - when it was open boarding I'd find the monitor closest to the gates to stand at poised. Now you book your seat, I wait for boarding to come up, then saunter down, use the loo, and queue up at my leisure.
Reservations don't have to be compulsory for that to work. They just need to be available to everyone other than the very last-minute walk-ups. Even better if there is a facility to cancel them (and a motivation to do so, e.g. a £2 charge for them but £1 back if cancelled before departure) so they aren't wasted.