I just want to put a couple things out there as supposition grows...
1. we should stop using black series, Galaxy’s Edge reproductions, or any other official consumer product as part of the equation. MAYBE one of those could be referenced, we know MR replicas have been reverse referenced— but in terms of practical FX, none of them would work for the needs of production. They are essentially toys. They don’t have the battery life or endurance needed for shooting duels days on end, (duels take several days to shoot). Also, it’s possible the ignition of the blade lights is done by remote. If Mando followed in the steps of the ST, those FX sabers also transmit XML tracking data to make animating the blades less time consuming and more automated in post. Toys are not going to help with any of this.
2. Just because production has access to the archives, that doesn’t mean they use them. TFA and TLJ both built versions of Luke’s saber instead of using the same prop. In fact, of all the lightsabers built for SW, only a couple belt-hangers have actually been re-used for more than one production. It’s often standard procedure, especially if it is a new prop team, to build from scratch. While I acknowledge Luke’s belt-hanger matching the Rylo, I think it’s still likely it was built for the show.