I think as long as the proposal is to migrate all Minetest development/chat to Element, this will be dead in the water for pretty obvious reasons.
People in this thread may have reasons for disliking IRC, but if the devs do not wish to move, trying to force them or cajole them is not productive. Perhaps the title of the thread itself doesn't help in that regard, since its wording suggests the aim is to abandon IRC and move elsewhere, rather than maybe endorsing/incorporating other FOSS chat applications more officially.
The wording including 'Element' rather than 'Matrix' is also prescriptive, since Element is only one of many clients for the Matrix protocol:
Forcing or pushing users to use one protocol is enough of a challenge, without trying to also push a specific client (especially if that desktop client is based on Electron :p)!
There are other potential measures that may go some way towards addressing some of the concerns at the core of this debate.
1. Declare official support for Matrix as a supplement to the official IRC. This Matrix chat could be the 'officially sanctioned' community outlet. People will still go to Discord if they absolutely want to use proprietary tools, but at least the line has been drawn about the project's ethos and there is an official more 'modern' option for people who want one but don't like using proprietary platforms.
2. Bridge Matrix to the IRC, ensuring that neither platform is isolated and giving some cohesion to the community. I proposed this on the unofficial Matrix chat itself, but it was not received positively. No judgment, I am sure there may be valid reasons not to, but it's important to keep in mind the Unofficial Discord
is fully bridged to IRC and has been for some time. Why give Discord preferential treatment?
Optionally, you could bridge Matrix to Discord too, but for Zughy and others, this might be unpalatable. It is also not entirely necessary as long as IRC is the hub/meeting point for these various platforms.
Bridge or no bridge, making Matrix an official option would certainly increase its visibility and activity.
To clarify, I am not a Matrix zealot trying to convert people, I am just of the opinion that Minetest as a FOSS project shouldn't be paralysed or embarrassed to say that it officially endorses, prefers or supports FOSS tools for its community.