You may immediately gain a card from the same location you just deployed to if a deploy ability allows it, but this is separate from the normal Lead gain step.

• If a deploy ability specifically instructs you to "gain" a card from the location you just deployed to, you follow that instruction as part of resolving the deploy ability.
• However, when you reach the final step of the Lead action (after deploying and resolving the deploy ability), you must "gain the top card of a location that you did not deploy to this turn" (see page 3).

This means:

• Deploy abilities can let you gain cards from the same location you just deployed to.
• The Lead action's gain step must target a different location than the one you deployed to this turn.

Source: page 3
"Gain the top card of a location that you did not deploy to this turn, then gain that location’s bonus."
"The deploy abilities of some cards instruct you to 'end your turn.' This indicates that you may not proceed to gain the top card of a location or the deck and the corresponding bonus."
"Do not gain a location’s bonus if you gain a card through other means (e.g., if a character card says, 'Gain the top card from Luna')."

Summary:

• Deploy abilities can let you gain a card from the same location you just deployed to.
• The Lead action's gain step must always target a different location.
• Gaining a card via a deploy ability does not replace or affect the requirement for the Lead gain step.

Source: Core Rulebook (pp. 1, 3, 5, 6)