That's correct. I tested it the other day. Goes to voicemail on their end, and nothing happens on my end.
On my dad's LG Flex, 'call control' kicks in after a very brief ringtone start and it blocks the call. I told him I'd rather not know the blocked person tried to contact me at all, and he said he would rather know. That kind of thinking is just... drama if you ask me. Always wanting to know what someone is up to. No thanks. Block and done. Thanks, Apple!