Forget about cloud computing and browser based applications. It will never work and will always have problems.
The current issue is not really with Java. All NPAPI support is being removed from all browsers. So this affects not only Java, but also Mathematica CDF's and any other plugin which uses this technology.
The correct approach to all of this is as follows: Maplesoft makes a free player available which runs the apps. The player is basically the Maple engine. A user installs the free player once. Then to run any app, down it and double click on it. The player runs the app on the PC or the mac or linux. The app does not run inside the browser and not in any cloud thing.
Much better support and a more reliable software, since one does not have to deal with cloud issues and the internet and browsers and all these problems.
With Mathematica, it has the CDF player. Once installed, one can download any CDF app and run them on the PC or mac or Linux.
Given that it takes a second to download anything these days, I do not see why one must be attached to a cloud thing instead of simply run something on the PC or the laptop, and in much more reliable way.