They said that rebreeding will be done automatically between updates for those who have given birth so it will sort of be a rotation of pregnant, heavy and birth. Also technically most of your Pokémon are kept on the ship while you go into the region to capture more that's the loop, meaning that it wouldn't be possible to do that because your not on the ship. They could add some in universe work around like a tablet with a camera of some sort but they already have their work cut out for them when they get back to work on the next update.