Well for starters, any modern web browser with JS disabled is going to display the original page just fine, but will not be able to render a canvas-based solution. That may put the user outside your target demographic, which is fine, but it is worth being aware of.
What exactly do you mean, the original animation was done in JS?
Ignoring the use of JavaScript in the old demo, is there an individual on earth that uses a modern web browser with JavaScript disabled, wants to order a personalised Apple product, and can’t enable JavaScript back for previewing?