Like, I just finished it today and the end left me so shook I've been thinking about it all day. And its a permanent cliff hanger bc no Half Life 3 or No Half Life 2 Ep 3
Playing through some of Half Life 2 (and its episodes) you can see where TF2 ties in to Half Life's universal structure. But considering Cave Johnson's multiple multiverses, TF2 most likely takes place in a separate timeline