One the key idea I think is to let player host listen servers easily from the menu
A button to start custom games will be added soon, listen servers are not planned at the moment.
and hosting a dedi requires [...] a server on which you can host it
Not true, you can easily host a dedicated server from your home computer and network, hosting a listen server would take just as much preparation in terms of portforwarding and firewall settings.
this would come to replace the whole matchmaking thingy but it'd connect the player to a server with a proper ping, a minimum amount of players, and a certain game mode
You can sort the server list by ping, players and filter by gamemode, there isn't that many servers, this isn't really needed currently. Maybe something to consider for way later. There may also be matchmaking for IW5 in the future, as, IIRC, it's also planned for T6.
I think it'd be cool if we could get this in PlutoT6 as well
See previous paragraph.