This is really normal for most small companies with good security posture, honestly. The company will pick one platform where endpoint management is functional, and require it. Code and secrets can't live on machines without endpoint management.
If the productivity/hiring/morale hit from requiring one platform becomes too great, then they'll get IT to figure out how to manage other kinds of endpoints. But in a small company, trying to manage disparate endpoints across multiple OSes is hard and expensive, but allowing corporate secrets on unmanaged endpoints is also a bad idea. So, this is the trade-off.
If the productivity/hiring/morale hit from requiring one platform becomes too great, then they'll get IT to figure out how to manage other kinds of endpoints. But in a small company, trying to manage disparate endpoints across multiple OSes is hard and expensive, but allowing corporate secrets on unmanaged endpoints is also a bad idea. So, this is the trade-off.