Why? Specifically, why the link removal - those are packages we create and maintain. We can of course mention that other people out there also package it and that you might check with your distribution etc.
That information is currently available through the community contributions section where the relevant section is https://docs.syncthing.net/users/contrib.html#packages-and-bundlings. And I think that’s generally a reasonable approach, as these are volatile and we don’t want to link to outdated/discontinued efforts on the main page. Official packaging that is less likely to just disappear might make sense to be referred to directly in that section.