The Linux Mint team has released LMDE 6 for download. LMDE is the Linux MInt team's backup plan in case anything back happens to Ubuntu which is the base of the main Linux Mint versions.
The Linux Mint 21 ISOs are being tested by the development team. This usually indicates that we are just days away from them being made available for public consumption, as long as the tests pass.
The Linux Mint team has released a stable version of the Upgrade Tool so LMDE 4 users can now upgrade to LMDE 5. Unfortunately, you still need the terminal to install the Upgrade Tool.
The Linux Mint team is finally working on an upgrade tool that will give users a graphical way to upgrade to new major versions of Linux Mint. It will be available in a couple of months.