No, the maps offered here are in exactly the same format as the Garmin "official" maps and all other third party maps based on data from OSM (including the Garmin's own TopoActive and related maps that use OSM data).
This is no different than asking "if I install a third party App on my iPhone or Android, or a third party application on my Windows PC, Mac, Linux or Chromebook, will it invalidate my warranty?" The answer is of course not!
Don't believe me, here's a quote from DC Rainmaker:
"Note that while Garmin would prefer you buy the maps from them, they actually go out of their way to allow you to download maps from 3rd party providers. They simply note that it’s unsupported (but doesn’t void any warranties or such). Meaning that if the 3rd party map data isn’t perfect, it’s not their fault. But here’s the dirty secret: It’s the same underlying map data."
If I was offering a firmware download for Garmin devices, or if the maps changed the firmware, then the answer would be yes, but I'm not offering firmware and nor are the maps modifying the firmware in the Garmin, just like Garmin's own maps do not.
So, the answer is still no, it has no effect on your warranty for your Garmin device.
Related Articles
Using the Map in QMapShack
The GPS version of the maps will work in the OpeSource desktop application known as QMapShack (this is the nearest that you can get to Basecamp on Linux, without installing WINE and trying to get BaseCamp to work via that). You can find out more ...
Do the Talkytoaster maps use more battery than Garmin maps?
No, the Talkytoster maps do not seem to have any additional battery drain/impact than the Garmin supplied ones (and they almost certainly have less battery impact than the OS maps will); I've certainly not noticed it on my Fenix 5X, my Fenix 6x, my ...
BaseCamp & Garmin Explore
Garmin BaseCamp was the replacement for Garmin MapSource (both are desktop applications for Windows or Mac). BaseCamp allows you to plan (and upload/download) routes, tracks, waypoints (and other data) between you Garmin devices and your computer. It ...
How many maps can a Garmin device support?
As with most things Garmin, it depends on Garmin imposed limitations, not on the available storage, for maps (internal and/or MicroSD card size): There are two limits that are imposed by Garmin (both in their device firmware and their file system), ...
Can I use the map(s) on multiple devices?
Yes you can! Unlike Garmin, our Talkytoaster TT HD Topo/Topo Pro maps are licensed per customer/user, not licensed per device (unlike Garmin's own maps) so they can be used on as many Garmin (or other compatible systems) as you personally own (for ...