Is Focal 726V an upgrade over Monitor Audio RS6 ?

I think the Bryston/Focal connection that you have seen at dealers is just a coincidence. The Bryston dealer in my area carries B&W and Canton. No Focal. Audio Advisor is a large Bryston internet dealer but no Focal. Music Direct carries Focal, but no Bryston.

The Chorus 726v is a nice speaker but IMO no better than the RS6 than you already have. And the RS6 is an extremely good speaker! Now if you were jumping up to the Focal Electra line, then thats a different story.

If you swapped, I would consider it a lateral move. The most you may achieve is getting a more lively speaker as Focals are known for being bright. But that doesn't necessarily mean better. I would stick with the RS6's.

I run Bryston amplification and Ihave noticed that many Bryston dealers also carry Focal...hence why I was curious if the Focal's may be a great fit....or an upgrade in general.

No. might be slightly better if you listened to Classical music, but even then more of a lateral move.