I was pleasantly surprised to see 1.4.3 in Debian Stable Backports.
But yeah... Fedora, and even Ubuntu to some degree, seem to be lagging considerably. Bigger, slower wheels grinding, I guess. Though last time I looked at the Fedora sigil package, there seemed to be an outright air of abandonment in my opinion. Ubuntu's a bit of a disappointment since I've tried really hard to make sure that the latest Sigil will build on Ubuntu 18.04 with stock components. They may finally get close about the time I have no choice but to target their next LTS version. Support for 18.04 is pretty tenous.
I've not checked out the Chocolatey Sigil package, yet. If they're using the official installer contents, it's probably all right. But if they're trying to maintain linux-like system versions of Qt5 and Python3 (that all other packages share), there's likely to be some plugin breakage.