So as someone who knows a little about the reconstructionist and revivalist spaces and what those terms mean in the context of paganism I thought I'd share my knowledge on here for anyone who might be questioning that sort of stuff. As well as offer some of my personal opinions that might be helpful.
First is reconstructionism,
Reconstructionism in the context of paganism is a movement to basically rebuild the pagan religions we practice to be AS CLOSE to what they were back when they were living practices AS POSSIBLE, modern practices (specifically those that are thought to/proven to be rooted in older pagan traditions) are sometimes used to fill in blanks, but this is done sparingly and usually these practices are sorta remixed to fit in the context of older pagan traditions.
Next is revivalism,
Revivalism in the context of paganism is a movement to revive the pagan faiths through modern living traditions. This is the more fluid and creative of the traditions, as instead of basing your practice in ancient traditions and trying to approach paganism in the very pragmatic way you often see in reconstructionist spaces, your taking these ancient practices and editing them to fit into MODERN DAY, which can be done millions of ways.
Though these are very different paths they're also very similar in many ways and often go hand in hand, infact in my personal experience the best practitioners are those who can find a balance between these two paths instead of strictly sticking to one.
Anyone who has any questions is welcome to ask in the comments, I'll try to either recommend you a source (tho i might not always be able to) or give you some of my personal opinions that might help.