This has just started happening, I hadn't noticed it before.
Basically when you see the message in top right corner that is safe to leave, you will still receive a loss. Hoping it doesn't also count as abandon on my end.
No its still a loss. If your team is good enough to play 5v6 and win itll count as a victory. If all players leave and somehow their creeps push the win then they will and vice versa i think. Ive gotten a win on a match i know everyone left but i was the last one (and my team member is the one who abandoned)