The only reason I could see them going through that effort with an old title while new titles are selling out consistently would be to maintain a licensor relationship, or maintain an IP to show it's still "in use". They don't "need" to re-release anything old while they're new machines are selling out consistently, even if the market is finally equalizing/cooling off. What IPs or licensor relationships could we see this being a case for?
The suggestion of Spider Man seems reasonable. There's always something "new" with Spiderman coming out.
Metallica would be cool, but bands seem to be very easy to license so I'd bet they have the next several band pins in sight already.
I wouldn't think it would be Walking Dead since the main series is over.
I think LOTR could be the best "long-con" from Stern if they opt to re-engineer and re-release:
LOTR was made during the old ownership of the IP. With the new series on Amazon there could be a new "LOTR"-adjacent machine on the horizon through Rings of Power. Even if the show is "meh" in season 1 (personally I loved it, but "the internet" seemed torn), based on theme alone it would sell like hotcakes, and we've all seen many "nebulously rated" properties get a cornerstone. The show is planned to run 5 seasons, so there is plenty of time for a RoP machine to be developed and released. I could see them wanting to secure the license ASAP, but wanting to sit on the license until at least season 2 is out, both for potential hype and for more assets to be available. Is it possible that Stern would re-engineer and re-release a modified LOTR just as a means of creating the relationship with the new owners of the LOTR IP immediately and having a product sooner than later, therefore bringing the new IP holders to "their side"? Presumably the relationship forged with the new IP holders would help open the door to Stern forging a relationship with Amazon for RoP.
In this scenario, worst case would be that Stern could sell a metric shit-load of Spike 2 or 3 LOTR, which would make everyone (Stern, Licensor, fans) happy, even if they didn't get the RoP license. Best case we get LOTR and a Stern RoP. More pinball is (almost) always a good thing!!
If not for the new IP ownership of the LOTR universe, I would automatically assume JJP would have dibs. But with new ownership, I should see all bets being off and Stern swooping in.