Tommy and Lindsay run out of the house screaming shortly before Michael attacked Laurie for the third time. After Loomis shot Michael off of the balcony, he gets up, walks off of the lawn and Tommy and Lindsay are nowhere in sight... Because Michael killed them.
Tommy shows up in Part 6 (still traumatized by the events of this film even though it's 17 years later) and a teenage Lindsay appears in Halloween 4, so not necessarily, depending on the continuity that you follow.
Plus Laurie told them to go over to another house and since Michael was busy attacking Laurie at the time, it's safe to say that they had plenty of time to run away.
Whaaat? When would have had time to do this... this sequence is in real time and Michael is never unaccounted for.