Swindon

The 50th anniversary had Tom Baker make a cameo as a future incarnation straight up telling 11 that he might "revisit some old favorite (faces)", then 12 subconsciously chose a face from someone he met in one of 10's episodes, and then 14 took 10's face again for a few episodes. So yes, they explicitly opened the gates for a previous actor of a different character to pick up the role (and even a former Doctor). I think there have also been some rumors coming and going about Jenna a couple times, ever since Clara pretended to be the Doctor in a couple of episodes.