Agree that current rules disallow removing snow from the branch although snow can be cleared from a basket or tee sign (say short tee in line of shot from long tee) under 803.01 B3 pertaining to returning equipment to proper working order. But should it be more lenient in future rules?
Here's an excerpt from a related 2002 rule (803.04B): "...A player may move obstacles between the lie and the hole that became a factor during the round, such as spectators, players' equipment, open gates, or branches that fell during the round. Where it is not known if an obstacle has become a factor during a round, it shall not be moved...)"
Branches and snow can fall to the ground or to suspended positions on branches, baskets and signs either before or during a round. If seen to happen during a round prior to 2006 when the rule became more like the current version, players could move them before throwing.
There are plusses and minuses with the past and current rules but I'll offer a compromise version for the future:
"Player may clear obstacles and creatures not intentionally part of the course within a 2m radius vertical semicylinder above the playing surface in front of their marker, not limited to typical obstacles such as unattached branches, broken glass, trash, snow and spider webs."
When removing suspended obstacles, the branches remaining that suspended them will still provide a similar challenge. In the case of items on the ground, it seems like allowing their removal would increase safety for follow through. The only caveat might be the need to add something like "in a timely manner", so players don't take too much time to shovel, move a huge log with help, or remove many pieces of glass.