I agree regarding OpenWrt, I guess it’s more about additional software through LXC and Docker. There’s a recent thread regarding Nextcloud that seem to only support 64-bit going forward. The reason seems to be some 3rd-party library which they use, see the mentioned issue for details.
The Nextcloud example is a good one because it wasn’t the Nextcloud team that decided to drop 32-bit support in the first place but one of their dependencies which neither Nextcloud, OpenWrt or Turris can control (or want to maintain). X64 servers have been the norm for many years so it doesn’t come as a surprise that server software projects happily drop 32-bit compatibility.
In any case and independent of any long-term Turris roadmap: I’d be surprised if any new hardware wouldn’t be based on a 64-bit-compatible SoC.