If software 1 is the only software used in the network (or used by the very large majority of the nodes) and whatever decision its developers make ends up being run by the nodes, then the answer is Yes.

The trick here is to be sure there are multiple implementations and all progress in the network rules is achieved by rough consensus (you will never please everyone) between developers, validating nodes and miners.

Miners and nodes can always reject to upgrade to newer versions, but if there's no alternative software that they can rely on, progress will stall. The open-source nature of the Bitcoin Core code helps mitigate this risk.