While it's true there is a tip-up seat next to one of the cycle areas, I can't ever recall there being a notice that stated it was a dual-use area, where wheelchair users were given priority. Not to say there isn't one - I just can't recall it.
I'm also sure I've had a cycle reservation that's specified the coach containing that rack (I remember it being a tight fit to get my wheel past the tip-up seat), although that could be down to coaches being mis-labelled.
Is it also true that cycle reservations were compulsory before the introduction of HSTs?
In any case, to say it's incorrect to claim that they've cut the available spaces from 4 to 2 is disingenuous at best, and an outright lie at worst.
I've been commuting Glasgow to Aberdeen with a bike for many years now. On 170s it's two racks, one on Coach A and one on Coach C, each capable of taking 2 bikes. Never have I seen a sign stating that bikes might have to be moved to give priority to wheelchairs.
Now, on some 170s, in the labelled wheelchair area opposite the bike rack on Coach A, there is also another bicycle sign on the window. This implies it is possible to fold away the seats and hang a couple of bikes on the mini-table. However other 170s don't have this sign. So to me, it means that 170s have 4 designated bike spaces, plus an additional 2 that might have to give way to a wheelchair user.
When the HSTs were originally announced, all the Scotrail/Abellio PR referred to these trains having 6 bike spaces, 4 being bookable end to end and another 2 for part journeys. Currently the classics do have space for 6 bikes at the end of the standard class carriage nearest the power car, but the refurbs only have the 2 vertical hanging spaces in the middle of the train, which I have yet to see anyone managing to actually squeeze two bikes into. One guy's bike was so difficult to put in even on its own that the guard gave up and it was just left outside one of the toilets, which was OK as it was out of order..... I don't know why the end to end spaces aren't available yet and why they are going to be in the power car rather than the adjacent carriage like they are in the classics.
So, 2 spaces is way short of expectations.
Booking was always described as compulsory on that route, though it is never actually checked.