When game developers move on to two different projects, they rarely return to the IP that they left behind. WIth two new projects underway, it means many years of no eyes or work on anything Battletech related. This means that HBS ever returning to Battletech would require them to build a new engine, new gameplay, new features, etc. Such an undertaking requires a lot of resources and such a business decision is not taken lightly. If they've already decided to abandon a possible sequel for this current game, don't expect them to ever start making a new Battletech five to eight years from now.
This video and Kickstarter post is basically a farewell for HBS and Battletech.