It was announced to developers on Friday that MIPS64EL is now being treated as a Debian out-of-sync architecture due to an ongoing shortage of build daemon "buildd" resources for the architecture. Thus migration of packages to Debian testing won't be held up now until MIPS64EL builds complete.
Debian developer Sebastian Ramache wrote in that announcement:
"For the future of mips64el as release architecture in trixie, we will closely monitor the buildd situation. Without the required buildd resources to keep up with the demand in unstable, (old)stable and for security uploads, the architecture is not suitable as release architecture."
As most Phoronix readers are aware, MIPS as a CPU architecture is at a dead-end with no further development planned. MIPS is now focusing on RISC-V while Loongson as a formerly notable MIPS vendor in China has now evolved it off into their own LoongArch CPU architecture. So unless Debian developers somehow find access to more MIPS64EL-compatible hardware as well as interest in maintaining the architecture, for Debian 13 "Trixie" in two years it's very well possible MIPS64EL will no longer be a release architecture.
Debian also already dropped its 32-bit MIPS little endian "mipsel" port a few months ago. The original "mips" CPU 32-bit port was dropped after Debian 10.