Recently purchased a Nest Protect from Amazon, I ordered the battery version because there was no AU/NZ wired edition stocked anywhere reasonably trustworthy nearby. It came labelled with a Replace By date of November 2027. I've returned it. Fun fact, the box serial has the format ########WWYY#### so you can at least tell if it's worth picking up if you come across one in a store.
On further inspection other folks appear to be receiving similar stock, with some ordering a 4-pack and seeing all different manufacture dates ranging from 2016-2022. On further investigation, the Amazon seller isn't even Google, it's an independent. It seems to be an odd situation where Nest isn't moving Protect stock as efficiently as other product lines, and there's very little recent information about it, despite glowing recommendations from tech folk and more generally.
In looking for solutions, I'm stumped. I've widened my search to basically anything that detects smoke/CO that could potentially integrate into HomeKit, HomeBridge or Home Assistant. Outside of Nest, I'm not interested in relying on a cloud service for operation for obvious reasons, and with Google characteristically killing off the brand I don't hold much hope for Protect either. My last resort might be to buy a Cavius and an Apple HomePod for the alarm detection push that provides.
Has anyone had recent experience procuring such a product or system?