Hi BrechtSchamp,
sorry, I had been a bit short here:
This time, the vMX100 license is a trial license. I can imagine that in case of a trial license, Meraki is in the "driver seat", i.e. forces this site to be upgraded ("first shoot, then ask").
For licenses and devices that the Customer really bought, the Customer is in the driver seat for firmware upgrades. This means he could switch off automatic firmware upgrades and schedule them to a off-peak day or weekend or even postpone them until the firmware has reached a kind of maturity.
Rgds,
Andreas