Walking into a reformer studio for the first time is intimidating enough without also being the only man in the room. A dedicated men's class removes that barrier entirely, and it gives studios a clear, marketable offering.
The classes don't need to be permanent fixtures from day one. Start with one slot a week at a consistent time. Consistency matters more than frequency early on: men are more likely to commit to something that's predictably on the calendar than to a one-off trial class.
Once the class has a regular group attending, word of mouth does most of the marketing for you. Men bring their training partners, their brothers, their co-workers. A men's class that works becomes self-sustaining.