This is most definitely a protest by China. The official statement holds no weight whatsoever - anyone who's been to China and seen the speed infrastructure projects are completed should know any venue remodeling work can be done in time if they wanted it so.
I haven't been following the news the last few weeks so not sure the order events unfolded, so its unclear to me whether the Chinese figure skating judges suspensions (sidebar: they probably deserved this, but they also look to be singled out and weren't the only ones to deserve it) were an additional consideration for China calling off events, or if that's ISU countering China's event cancellations ...
In any case, I suspect China's decision had a lot more to do with short track (the crown jewel of Chinese winter sports) than figure skating. I followed weibo a bit during the Olympics, and most people were in agreement with figure skating results (Hanyu gained a lot of layman fans haha). Different story for short track - national outrage! IMO both China and Canada were screwed over (singled out for DQs whenever there was slightly questionable contact - and the South Koreans got away with SO MUCH). The only individual event China won was the men 500m when the guy was just ahead the whole way (including every heat race - setting and then breaking his own world record), and afterwards the gold medalist literally said "I had to just give my all and be ahead to not give the judges any opportunities" - can't get more blunt than that!
Public opinion against the IOC and ISU is pretty toilette level there now, so China gets two birds with one stone with this move - (1) show the ISU it is not a pushover and (2) cater to its netizens' calls for a strong retaliatory response.
I feel bad for the Chinese skaters who'll have to now duke it out off home turf, but from the Chinese Fed's perspective, the positives of demonstrating its clout to the ISU and the good PR at home for doing so probably outweighs all that. At the end of the day, they'll have the big event on home soil in 2022, and I don't see China being overly focused on figure skating anyway for the home Olympics - there's at most just 2 or 3 medal chances. They'll be pouring more resources into speedskating and the snow sports.