Every 20 minutes, Pinpointe checks to see what contacts are due to be sent any autoresponders or trigger campaigns. Any contacts that meet the filtering requirements at that particular time are put into the queue and will be sent. 

In short, yes, if you change details after sign up and they then qualify for the autoresponder when it is due to be sent then they will receive it. However if they did already qualify for the autoresponder or email campaign and they change their details and then become invalid at the time of the send they will not be sent it.