Not entirely true. I don't wear tight clothes anymore as I grew out of that phase, but if you're shredded and have a decent amount of muscle it will most definitely show through clothes. The traps and shoulders should look good, shirts should have a tapered look, long sleeves should wrap around your muscles nicely and thighs should be visible when you were pants.
I think a lot of guys are convinced that fatceps are the be all, end all. No one cares about these chubs. You should be able to take your shirt off at any time and look good too. And unless you're wearing a sweater, your muscle should be visible from under your clothing. If your muscle can't be seen with clothes on, it means you're smooth as a turd.