Early Meta's for Veilguard seem mixed, but slanted positive. Which seems pretty classic Bioware. In their heyday, after Mass Effect 1 and Dragon Age Origins, their games tended to be uneven, but still very very good. They had a tough decade after the DAI launch with Andromeda and Anthem bombing. I watched a couple video reviews with gameplay, and from what Ive seen it looks incredible. Combat looks more like it integrated the Mass Effect party system into DA.
It looks like it will be 100 hours for completionists. I went back and looked up my farthust DAI playthrough and it was about 120 hours with three DLC completed. So even without being "fully open world" , you are getting the same amount of content as DAI