Nobody ever trade a #1 proven goalie
It doesn't happen, unless in extremely rare occasions aka the Bob Trade
It has happened loads of times in the salary cap era alone. Some names include Bob, Schneider, Varlamov, Luongo, Roloson, Andersen, Anderson, Ullmark, Allen, Kuemper, Fleury.
Some of those had limited experience (e.g. Anderson), but many of them had years of experience being a #1 goalie. They just happened to be getting older or have a younger goalie ready to take over.
It's not like a #1C. If a starting goalie is performing well, but not like a top 5 goalie, he's pretty replaceable, especially if you're not going to compete any time soon.
That being said, this sounds like an obvious overpay for a Habs player proposed on the trade forum, so I give it like an 90% chance of happening.