Flash was euthanized by the tech
community that helped create it because it was a permanent security
The tech community didn't create Flash, it was a plugin for Director for creating vector animations within that application. It was created by media people for media people who worked with it.
The 'tech community' more accurately Adobe screwed it up so beyond repair it's ridiculous, always has been, almost to the day they sucked up Macromedia.
It's not the content which creates the security issues within the networking/internet environment, it's the installation and functionality of the player/s and what people can code into them, which again , Adobe were responsible for.
Flash was never created to do what it has been doing since Adobe took it... People who've worked with it since MM days know this and many articles and such explain that. Unfortunately for many years there simply was no other tool which could deliver animated content via the web and browsers.
Flash was never created to be a game development platform as it has been used over the last 20 years or so, in saying that it's not the content that creates the issues, never has been.
Should it be mothballed? Absolutely, should have been done 15 years ago, but not because of the content created with it. There isn't anything wrong with the content, in fact Flash is extremely powerful for what it does and does best. AS can be coded to do very impressive things, if used as it is intended.
Unity is the flavor of choice for game developers mostly now, you can develop applications with it if you choose to, should you? No, it's not really for application development but it can be done. This is much the case with later Flash work, ya you can do what you're doing, we don't recommend you do though. People did anyway.
WGT should never have used it to create this game, that's a given, in saying that, the game should show you what you can do with it. There is a way this game can continue on as is, it would take a bit of work on WGT/TG's part but it could be done. Question is, why bother? Flash support is going away by Adobe, I don't think WGT/TG wants the headache of becoming the support point for the player and installations.
Flash was great to use, I worked with it for ten or so years when it was part of Director, too bad that it gets the bad rap which it does. It's Adobe which deserves the bad rap truth be told.