This Acer Forum Thread answers your question: https://community.acer.com/en/discussion/567838/i-would-buy-the-amd-acer-predator-helios-500-tomorro...
Basically Acer needs to update the Laptop BIOS to make it compatible with the Ryzen 3xxx Processor as long the the Motherboard, technologically, is able to support the new Rzyen 3xxx.
You need to contact Acer Support and ask them if your laptop will have a BIOS update to support the new Ryzen processor or if even you laptop is able to support the new processor even with an BIOS update.