They’ve released more information regarding the carryover.
Check everything here from cake941’s post: H3 Pre-Launch Guide (Progression Carryover)
I’m highlighting some of the information below, but check the above thread for the complete details.
Progression Carryover
The following progression will be included in the carryover process: player profile, XP rank, location mastery levels, location mastery unlocks, challenge progress, challenge unlocks and Elusive Target suits/unlocks. Savegame files are not carried over.
The carryover process requires an IOI Account and can only be done through a web browser, it’s not possible to do it in-game. We will have the website ready to go before launch, but it is not live yet. Once it is ready, we will share the news via ioi.dk and update this post.
Here’s more about how it will work:
– Progression can only be carried over from HITMAN 2, including progression you have from the Legacy Pack (HITMAN 1 locations within HITMAN 2).
– Progression can only be carried over from within the same platform.
– Progression carryover is a one-time process, meaning once you have performed a carryover for a particular platform, you will not be able to do so again at a later time.
– When you complete the carryover process, your existing HITMAN 2 progress will remain as it is (i.e it will not be removed/deleted). Your progression in H2 and H3 will NOT be synchronised.
– If you have already started playing HITMAN 3 and THEN choose to perform the progression carryover process, you will lose all progression earned within HITMAN 3 up to that point. We recommend you carryover progress before starting HITMAN 3.
the ICA Electrocution Phone has been retired and will not be available in HITMAN 3.