So the Protea test team has arrived in Pakistan and the test series are scheduled to start on 26 January 2021. While he two tests will be in progress the T20I squad will arrive in Pakistan,
After the tests are completed the test squad will return with Boucher to prepare for the three Australian tests and his Deputy will stay on to deal with the 3 T20I games, According to Boucher the emphasis is on the tests against Australia and of the test squad "only one or two" test squad players will stay on for the 3 T20I games and the team will be made up of mainly youngsters.
So who will the two that will stay on be? It depends entirely on the selection of the T20I squad, but the one or two players could perhaps be De Kock and Sipamla. The former has extensive experience of sub-continent pitches, bit if the emphasis is on the Aussie tests two weeks later - then Du Kock may come back with the main team. My guesd is the other player to stay on will be Verreinne.
One would assume that the T20I squad will be announced this coming week. Apparently the squad will virtually entirely be made up of newbies and in view of the planning their may even be a new captain assigned to lead the team in the T20I games, since De Kock may be needed in the preparations for the Aussie test series. That appointment may be the start of the search for a new permanent captain for the test side.
If the T20I batsmen do well in Pakistan some of the test batsmen may be in danger of replacement especially if the test batsmen fail in the test series in Pakistan.