I’m not sure what e.foundation is planning. But I also don’t know what Samsung or Huawei or xiaomi or all other companys are planning or google itself. As far as I know google is planning a new phone os , fuchsia.
What I mean is, that you will never know how long your device will supported.
Buy one of these in… 3 years or so? It should be ready for normal daily use by then, Or maybe one of these next year. Either way, Linux never goes out of style…