this is true.

once you have a rear wheel with a rim that sits evenly between the seatstays and chainstays when mounted and that involves a threadon cog or ss freewheel, you have pretty much already made a choice as to the perfectly straight chainline. the rest of it involves matching it to the proper crank and BB.

BTW, a ss freehwheel can be adjusted laterally outward to some extent by judicious use spacers. and some fixed gear cogs are dished to allow two discreet chainlines.