DJI got them selves all in a mess with the introduction of the Pro and V2, both are identical aircraft but I believe now that the V2 is T601 and the Pro is T600 like before, but the pro has also shipped as T601 as well.
As for the
Inspire 2 I have heard a whisper is not going to be until October time, I honestly think overall drone sales are down and DJI may be holding back, you only have to look at the forums and see numbers of people are down.
Whilst I think the P4 is selling very well I don't believe it's in the quantities the P3 did, I spend most of my time on RCG and the P3 thread was crazy for 3 months after launch with it adding 20+pages a day sometimes, the P4 has just not been the same, the Apple affect may begin to kick in and people start to miss a release, The P3 and P4 have also stole space from the inspire and TBH the P4 is shockingly good, the camera and gimbal is much improved over the X3 and has none of the distortion at the top bottom the X3 has and the gimbal is much better at keeping level. If you don't need interchangeable cameras or duel ops then the P4 is a very real and cheap and capable tool, In fact the P3 Pro is crazy value rite now and can product almost the same results.
The P4 is cheaper, has batter battery life, camera over the X3, cheaper batteries, cheaper consumables, yes it's a white blob and does not give the "professional" look but it's a very impressive tool.