TL;DR, you can ignore the message.
Several folks have noticed that, since about yesterday, if you run
the SaxonJS 2.5 xslt3 Node.js command line processor, it
prints a scary “no longer supported” message.
Sorry. Our bad. The message is only informative and has no effect on the performance of the processor.
We support SaxonJS releases for at least a year and a while back (far enough back that I can’t easily determine when from the repository history), we confidently assumed that we’d always do a release at least once a year. So when you got that message, it was to encourage you to upgrade.
Except this year, we published a whole bunch of other releases, embarked on SaxonJS 3.0, shifted our web infrastructure around, and did a bunch of other things. What we didn’t do was publish SaxonJS 3.0 within a year, and because we were heads-down on that, we didn’t notice that we hadn’t published a SaxonJS 2.6 release within a year either.
(It’s all a little embarrassing.)
We’ve fixed a handful of bugs in SaxonJS 2.5 since we shipped it, and we’ve identified a slightly larger handful that we’d like to consider fixing before we ship a SaxonJS 2.6 release. But we will ship it, as quickly as practical.