Because Jason left, Han left, russia is somewhat unpopular at the moment so probably anything eastfront related won't sell well, and nothing was announced about the future, bar a few collectors and re-selling RoF.
No inside info sorry, bare dry deduction.
Jason and Han leaving can have an impact but I don't think the current war in Ukraine will affect sales of Eastern Front-related content at all. After all, I'd say the vast majority of flight simmers play flight sims with little to no consideration for current political issues.
As for Flying Circus, the graphics engine has been completely revamped and it looks much better than ROF. I haven't flown enough of it yet to determine though if the flight modelling is significantly different.