I don't want to speak for Henchy as to why he's saying it wasn't that close of a series, so I'll offer my own thoughts (and perhaps they coincide with his):
I don't think it was a close series either, and pointing out that G6 went to 2OT and removing the ENG's you have 4 1 goal games doesn't necessarily change that either, imo.
I don't think it was a close series because, outside of a few periods, and G5 itself, the Avs never looked like they were a dangerous threat. Dallas neutralized MacKinnon/Makar/Mikko for the majority of the series (again, save for moments here and there). This series was like nearly every other non-Cup year playoff series when we got exited--you shut down the Top Players, you beat the Avs. This has been a rather annoying constant every year, save for 2022.
Let me put it to you this way: In the 2022 WCF, the Avs swept the Oilers 4-0, that featured 3 of 4 games having either an ENG OR being a 1 goal game (that 1 goal game being G4 and Lehky's OT winner)...do you think that was a close series? Or did you watch that and see the Avs, despite being behind at times, pretty much controlling the games? I mean, in my opinion, I think you could look at G4 as the one that Edmonton probably should have won, but after Toews got that early goal in the 3rd, it started to feel inevitable that the Avs would either win or tie it, at least (and instead they got a lead only to then surrender it and go to OT anyway but still win).
After having some time to reflect, I don't think the Avs really were all that well prepared for this series, or at least to go against Dallas. I had mentioned that I wanted Vegas instead of Dallas, because I don't like going against DeBoer teams...he just is too good at neutralizing the Avs and their specific gameplan. I think we would've had a better shot against Vegas (though, still no guarantee).