I think that's pretty far fetched. His silhouette looks nothing like Zoro and there is nothing else about him that really supports the idea. I even went and read the wiki entry about him just to be sure. Seems really unlikely.
Phew... I see. Let's see what Oda makes of these potential hints/links in the story. (I have become a bit careful with theories and hype around Zoro, because I kept being disappointed by the past couple of chapters and the lack of what could have been a great arc for zoro fans honestly.)
PS: Also welcome back! I am glad you decided to stay around! :)
Holyshit, Greenbull will neg diff the rest of the SH and Luffy won't be in the condition to fight anymore, but Zolo will overcome twice the pain and wake up again to save Wano from Admiral bastard