I've noticed that in most cases when a unit has an ability to search for and play another unit that it triggers the deploy ability for that unit. I would like to know, are there exceptions to this rule?
The definition of the Deploy keyword is as follows
Deploy: Trigger this ability when the card is placed on the Board.
This means that as long as the card enters the board, whether it be from a spawn or card effect, it will trigger its deploy effect.
If an exception arises, it would likely be in the card text of the summoner.