Yes, that's how it would need to work for me. One of the things I really disliked on Tumblr was that even when I carefully chose who to subscribe to and blacklisted a ton of tags for fandoms that didn't interest me, I was still seeing a massive amount of reblogged content. I would've killed for a box to tick to show me only the original posts of people I followed! What you describe would make the reblogged content opt-in for the reader, which would be great.