Your idea is sound, and the more people that pick up TM1 again means it will be more fun again. Sadly, I don't think you'll ever see the numbers of active people there that you once did. But it could improve a lot if people knew there would be people to play with once again.
A lot of old timers returned over the past two years, partly because they wanted to engage again with the TMX community before the new game came out. Also a lot of new players got United or came over from TMNF in order to get a little more diversity. So we saw things get more active than ever before. Some, like Ganjarider, liked Canyon and so they're still here. Others perhaps didn't like Canyon as much. Others might be lurking and waiting for Valley before they get more active again. Almost all of my LT clanmates aren't playing Canyon. A few have made the switch, but many just don't think it's for them.
There are a lot of people who do play Canyon, but also a lot of people who didn't make the transition. Maybe they should play TM1 until Valley comes out.
These waves of activity and shifts in where players are playing are quite normal in TM and have probably come with every release. It's just a period of adjustment.
That having been said, there's still plenty of fun to be had in TM1.
But I would keep in mind that you don't need to stop playing Canyon in order to enjoy some good times again in TM1. I play both, and it's like having 8 environments instead of 7. It just adds to the diversity and fun.
Of course, if you don't like Canyon at all, you don't have to play it.
It's your choice.
Hope to see you in TM1!