With the current state of recruiting, is the military offering more prior service slots and are they more likely to approve medical waivers?

I also have not read or seen official guidance that changed anything from the enlistment & accessions policies issued by Army Recruiting Command in Jan 2023. Your best option here is still to seek out a knowledgeable recruiter, even if you have to travel a bit to find one. It's unfortunate your local recruiters cannot directly give you an answer; nonetheless, they are the ones who can address any current policy changes that affect your reenlistment eligibility status and process any waiver that you may require.
RE-3 is a broad category code (medical or physical issues, failure to meet performance standards or administrative reasons, e.g. RE-3A, RE-3B, ...) Depending on the subcategory you are coded with (the reasons for the RE-3 code) the recruiter should be able to tell you if any of these are currently waiverable or not. And, very importantly, enlistment will also depend on the characterization of your prior service at discharge.

You might consider the Army National Guard. My son needed a medical waiver for his initial enlistment and the Army was a flat-out NO (Although he had two civilian consults, from two different specialists, that had found nothing wrong with him.) The local Army National Guard recruiter was willing to do the work needed to get him the waiver he was told he needed and was able to push it through.

Sorry, as far as anything I have read or heard that has not changed. Waiver with a three are pretty much unheard of. You are always free to try.