It enters into "dodgeing" manners.
After you accept the match up there is a timer (25 seconds or something) to connect to the server that the game is played, if you fail to connect in that timer you are going to be assigned with an abandon.
Dodgeing manner is applied heavly in high rank matchmaking to gain ILLEGAL MMR.
Do you have a history of your connection being spotty? I had this issue once and at the same time everything took a long time to respond and my Discord was breaking up as well.
The game coordinator doesn't really care why your connection to the game could not be established, thus giving you an abandon.
What exactly happened? Did dota2 client freeze? Or did it crash to desktop? If you have SSD and good pc components you should be able to quickly relaunch the game and reconnect, no? That's what I tried to do but failed, and the time in picking phase ran out before I could reconnect. Got me a 24h break from dota2.