Without full visibility into RPM's client contracts and...

Without full visibility into RPM's client contracts and agreements it is very difficult to say how the maintenance scheme works, but would be a good question to put forward.

I fully expect the subscription model to cannibalize the maintenance revenue and strongly disagree with @Jimmy_C. In general I would expect a subscription model (these days we often call this "Software as a Service") would provide a much higher level of support and more inclusions/updates than a perpetual licence.

Any analogy to buying/leasing/renting is flawed, because you never 'own' software (you merely license it), but even at the most simplistic level a subscription model includes updates and improvements as they become available, whilst a perpetual licence means updates are optional and come with additional charge. This distinction is a key part of the subscription value proposition - known and stable costs.

We should expect that the majority of support / maintenance income is linked to perpetual licence holders. Good news is that any licence holder can only 'get out of' their support / maintenance costs by buying a (more expensive) subscription.