If honesty is the best policy, then BB would have already told us what the plan is concerning the Flash issue of 2020.
Adobe announced in July of 2017 that they would not be supporting flash any longer come 2020. This game runs on flash. BB announced in their Ask Me Anything posts in November of 2017 that conversion of the game to HTML5 was not on the development roadmap.
Everything that has been done up to this point SEEMS to indicate that the game will be shut down at the end of this year - the addition of high end content (new endless mines), the addition of a new event (Valentines), the fact that they won't even say "We know it's an issue and we're working on a solution". All reasons to get players to buy and spend gems before the end of this year.
If honesty was the best policy, we would have an answer to the future of the game by now - at least an assurance to the players that it will be around next year.