Is this supported or do we need to do this ourselves?
There is no way to automate upgrades between versions, especially for vertical-solutions, even more so if they are customized.
So the Odoo programmer responsible for the customer, project and vertical-solution will have to do it himself manually. At some point, he could also create his own automations.
Remember: SPYN is a way to distribute vertical-solutions rapidly, so authors can focus on marketing, sales, user-support and such customer-facing activities, rather than installations, setting-up demos etc.