They appear to have been randomly selected from the Fan made Contracts of Hitman WOA thread. His first batch were contracts posted in thread in January/February 2021. This current batch were taken from January/February 2022.
God forbid there is a third batch, but if one does get forced upon us contracts from January/February 2023 will likely be selected.
Edit: Just as a note for combatglue - part of the reason why going this far back is perhaps not the best idea is that contracts that used things that were once possible in the game, but have since been patched out might be selected.