Licenses are sold separately from the hardware. For example, you could upgrade from the MR16 to the MR24 without buying new licenses. The same will apply for new products that are released in the future.
In general, all Meraki products follow the same licensing model. The primary difference between them is that with all wireless access points (MR series) the license is the same for all hardware models, whereas with the switches (MS series) and security appliance line (MX series) each hardware model has a different license. Example: the LIC-ENT-1YR (1 year enterprise MR license) applies to any of the MR access points. The LIC-MS220-24-1YR (1 year enterprise MS220-24 license) applies to the MS220-24 model. The LIC-ENT-MX64-1YR (1 year enterprise MX64 license) applies to the MX64.