There's certainly no issues with mixing R550 and R510 APs in a network, in principle.
What network management are you using, as the new R550 AP might require an update to your software. The good news is that all Ruckus network management platforms can simultaneously support R550 an R510 on the same version of software code.
I hope that helps,
@joseph_la_valle Thanks for confirming you are using our (Ruckus) Unleashed management platform.
Before adding the R550 AP into the network, I would recommend upgrading to the latest version of Unleashed, currently this is 200.11, as this will ensure support for the R550 AP model.
Here is a link on how to perform the software update: https://support.ruckuswireless.com/articles/000005422