As far as I know RLC was working on their site to get it to run without the use of Flash Player but they apparently ran into some issues and had to resort back to Flash for the present time.
Flash Player will no longer offer Support. Flash Players End of Life (EOL) is December 31,2020.
Java will be eliminated at some point in time but no definitive date has been set. Google still has 9 Years left on their Contract with Oracle the makers of Java Runtime Environment (JRE). I would imagine it will be some time further down the road. Browsers that are used today such as Chrome Based Browsers and Mozilla Based Browsers will operate without even having Java installed. The only place where Java still may be required if anyone still uses Internet Explorer 11. Since Internet Explorer is a Trident Based Browser it still requires some of the older applications to keep it running though no further Support or Updates can be made. Since most Software Developers are going forward with advancements and eliminating Internet Explorer from their developments, Microsoft will likely be dropping any Support for Internet Explorer very soon and End its Life.