The PLA doesn’t do things out of arrogance.
I know, that's what I am writing in response to Zeak.
I listened to a recent podcast by Yankee and Shi Lao about last year’s tank biathlon. They’ve been invited to an event by the soldiers who participated in the 2020 event and Shi also even got to drive the tank, so the information is most likely legit. China was on the cusp of winning of the finale but the Russian officer pleaded with the PLA higher ups to slow down (in a less direct manner) because the games were rigged so that Russia will be champion every year. In fact the kids at the champion ceremony only knows how to sing the Russian national anthem and didn’t prepare any other songs at all. China complied to save face for them. Can you imagine any other participating nations of doing the same?
I think this is caused by genuine geopolitical pressure since China and Russia are getting squeezed from East and West simultaneously. Even in its present form, the J-20 can simulate top of the line fifth generation fighters like the F-35 in some mission profiles, so at a minimum it could provide Russian pilots with familiarity with fifth gen tactics.
Let's hold our horses and wait to see what role the J-20s play in the exercises first.
There are many capabilities that a 5th generation provides that might be useful in the exercise, at this stage we don't yet know if it will be on the friendly side (red force), the opfor (blue force), or an intervening force (orange force), nor to what "extent" it may operate in any of those respective roles.
For all we know, perhaps the involvement of J-20 in the exercise will have relatively limited contact with the Russian participants in the exercise and they will only observe certain limited aspects of J-20's capabilities in an indirect manner.
Do you envision the degree of trust between the two countries will reach that stage in near future where China is comfortable including j20s in high level exercises? I believe relations are at a high at the moment. Helped by current circumstances where US trying to pick a fight with both powers and comically trying to drive a wedge between the two at same time
Or is it just China not wanting to reveal their top of the line stealth aircraft for time being?
Near future? I don't know.
We don't even know to what extent the J-20s are going to be involved in this particular exercise.