It is on UserVoice [1], and it has over two thousand votes there. They've marked that as "sorry, no plans," and they've marked previous issues as "by design" [2]. They use Chrome announcing plans to deprecate SVG animations as their primary justification, but Chrome backtracked on those plans after realizing that there were important use cases that mattered to the community [3].
> In the 15 months since we announced our intention to deprecate and eventually remove SMIL, we’ve heard a variety of opinions from members of the community. We value all of your feedback, and it's clear that there are use cases serviced by SMIL that just don’t have high-fidelity replacements yet. As a result, we’ve decided to suspend our intent to deprecate and take smaller steps toward other options.
I understand that they don't have an infinite budget, but it really seems like they made their mind up here years ago and haven't been interested in listening in the community since then. It's also a bit circular to "prioritize based on how common the standards are found used in the wild" when they're single-handedly responsible for preventing developers from using SVG animations "in the wild" in the first place.
[1] - https://wpdev.uservoice.com/forums/257854-microsoft-edge-dev...
[2] - https://developer.microsoft.com/en-us/microsoft-edge/platfor...
[3] - https://groups.google.com/a/chromium.org/forum/#!msg/blink-d...
