This is already the case. Download and verification of Tor Browser works very similar in tb-updater for Intel / AMD64 builds (from The Tor Project (TPO)) as well as arm64 builds (Heikki Lindholm). Difference is the download location (TPO website vs Heikki Lindholm sourceforge) and the OpenPGP (gpg) singing key.
tor-browser-linux-arm64-11.0.14_en-US.tar.xz.asc is signed with
gpg --verify tor-browser-linux-arm64-11.0.14_en-US.tar.xz.asc
gpg: assuming signed data in ‘tor-browser-linux-arm64-11.0.14_en-US.tar.xz’
gpg: Signature made Fri 10 Jun 2022 10:41:23 AM UTC
gpg: using EDDSA key 17646366EFF82DB13E5CCDB23A557859C963442B
gpg: Can’t check signature: No public key
But I couldn’t find the EDDSA key with fingerprint 17646366EFF82DB13E5CCDB23A557859C963442B or any key transition statement. Please advice.
To avoid any confusion, I haven’t uploaded my (new EDDSA) keys to any key server because there’s an older RSA key with the same e-mail which I thought to revoke but so far never got around to.