Following the similar decision made by Canonical, the Linux Mint project will drop support for the 32-bit architecture. The change will affect Linux Mint 20 and above, which will be based on Ubuntu 20.04 LTS.
Actually, this change leaves Linux Mint users with older hardware out of board. They have no choice but to with Linux Mint 19.x, which will be supported till 2023.
These days not that many distros ship 32-bit versions of Linux. For instance, my favorite Arch Linux distro has discontinued 32-bit ISOs a year ago or more. For an older netbook I use Void Linux. Other distros with a 32-bit option are Debian, MXLinux, are a number of others.
The blog post mentions possible issues with Steam and Wine, which require a set of 32-bit libraries. As of now, Canonical is about to ship 32-bit support libraries for 64-bit Ubuntu versions, so the problem is automatically resolved. However, if Canonical change their mind and Ununtu 20.04 will lack the proper support for 32-bit packages, it will be an extra task for the Linux Mint team.
Source: The Linux Mint Blog