You already created a post about this a few months ago.
Welcome is not irrelevant at all to new users.
Gnome software is not a list of software picked by the Ubuntu MATE team.
Both apps usually are seen as pros in Ubuntu MATE reviews.
This is not Windows. You can remove the packages you're not ok with. Unless you make your own distro, there will always be packages you don't like/need and tweaks to be done.
You can replace those two snaps as well with a PPA published by the same person. But since his Launchpad account might get hacked, I won't bother posting the link to it.