Well, does it? Are they moving devs from PDF.js to the Rust ecosystem? It seems more likely to me that they would either lay them off, or move them to the PDFium stuff. Same applies to Shumway.
What a backwards step either way. As for Servo, how's it doing these days? Is it anywhere near done? What terrifies me is Mozilla would drop Servo when it's 80% done, just like it did with all its other projects, because "well, we already have Gecko, and it works, and it's too much work to finish Servo".
Aside from Rust and some Firefox tech, I haven't seen anything concrete come out of Mozilla in a long, long time. Rust, FWIU, has its own organization and is no longer handled by Mozilla alone (thank god); everything else gets killed off like a westerosi wedding.