Sketch has to play catch up and get people back to software they already left. I know people who used Sketch for years that don't actually know that it has a web app now. They've moved on and aren't looking back. Tweeting about Adobe isn't going to accomplish much long-term.

There's an inflection point where a tool becomes part of a de facto industry toolset. If most of your customers and partners use Figma, you do too. Figma's reached that point and Sketch has been on the downswing for years. They were rightfully outmaneuvered by Figma, and now Figma has a massive pool of resources on top of that.

At this point they'll need to do a lot more than copy Figma. Maybe they can luck out if Adobe doesn't understand Figma and causes some damage, but I wouldn't count on it. Perhaps there's some enterprise niche they can start to fill out.