I have been developing firmware for Nordic chips for about 5 years now, and I have roughly the same amount of experience with Memfault.

The idea of Memfault is like Datadog for IoT stuff. The reality of Memfault is that everyone just uses it to push OTA firmware upgrades through the cloud, and capture stack traces on crashes. Sometimes you bolt on their metrics later, but 95% of the value is in OTA firmware upgrades and crash reports.

Nordic has started to assemble a juggernaut of a tech stack, and a collossal moat. They keep most of their Zephyr contributions outside the main source tree, in something they call the nRF Connect SDK. They've been developing vendor-specific extensions to Memfault's SDK for years.

The upside with Nordic is you get a complete embedded tech stack out of the box. The downside is that, if their stack doesn't doesn't offer what you need, you have to grapple with the incomprehensibly complex SDK in the entire industry. For some companies, it works great. For others, it's an attractive nuisance.

I don't know how much actually changes for either company with this acquisition. It probably isn't good news if you're ST, Infineon, or Microchip.