Over the phone, while ordering parts
I've sent ATI North America an e-mail and the reply was similar to yours ("I do not have a timeline however we have been told at this point there is no concerns. It is possible particular color/size combinations would possibly be discontinued due to lacking sales, but there is no end in sight for the bulk of the options" and "From everything I heard 3-4 years would be no problem, particularly if you have a 48" fixture which is by far the most popular").
It seems from what they've told me that they are almost as clueless as us. I ended up sending ATI Aquaristik an e-mail and I'm currently waiting for their reply.

