x86_64 will never die, it's too pervasive, and as much as mobile fans think the future is underpowered ARM with the actual processing being done by a third party sifting through your personal data (who generally use x86_64 anyway), reality isn't following their expectations.
And anyway, I've had 2 expensive pieces of software meant for professional production, that just stopped working over the years for various reasons. "Old" versions of Vegas Video don't work in anything past Windows XP. Same goes for "old" versions of Pro Tools. Also, with the old Pro Tools, make sure you don't have a dual core processor, because that breaks it too.
My point is, there are many factors which can suddenly render software obsolete. I wouldn't expect CS6 to run on anything but really old unsupported hardware in 5 - 10 years.
One of the best things you can do for your career is to remain flexible about the tools you use. Always be on the lookout for alternatives.
