Robert, yes Sir, the slide sight dimensions are the same between the old shield and shield plus. Cheers and stay safe!

Yes, these sights will fit and function just fine. Hope this helps.

Yes. "The Shield Plus will also be compatible with all previous generations of sights for the pistol. This backward compatibility is a great feature in and of itself especially for people who have already heavily invested in the previous versions of the shield."
thefirearmblog.com/blog/2021/03/15/smith-wesson-mp-shield-plus/