Either we don't have enough details about net-snmp, or you're trying to
push for not-valid-yet-another-exception.
It's more if a source package makes multiple binary packages, one of those being a python 2 package, and there are other temporary reasons why that python package cannot be updated yet.
The perl problem has nothing to do with python, except that problem holds up the update of net-snmp. The goal is to fix the other problem and remove the python module, but it will take time possibly.
I'm pretty sure net-snmp is not the only situation where the python binary package is one of the many from a single source. In fact these will probably be the problem ones because they're often a case of "make python bindings once then ignore" situation.
- Craig