It's not going to be the only supported Motorola device. It's the first device they're making with proper MTE support and has much better secure element integration too. Snapdragon 8 Elite Gen 5 was the only Qualcomm smartphone SoC with MTE support. Snapdragon 8 Elite Gen 6 and Snapdragon 8 Elite Extreme Gen 6 also provide it. It wasn't available in the Snapdragon 8 Gen 5 but hopefully it will be for the next generation.

Pixels fill the need for budget devices well via the 'a' series, especially when purchased as used devices. 7 years of decent updates from launch for budget devices is very unique and makes used devices much more useful.