There is a possibility the new Telltale Games (LCG Entertainment who bought the assets of Telltale and will continue the brand) will decide to sign with GOG to bring back a selection of the games to the store, but the exact titles depends on third party licensing, since some rights have reverted to the original rights holders and need to be re-negotiated, while others were still retained and transferred in the assets sale.
No word yet (as far as I am aware) whether LCG Entertainment is interested in selling games on GOG.com (I hope they are).
joppo: Very unlikely that they will ever be back
anywhere. Telltale filed for bankruptcy, fired all employees and is now pretty much defunct.
LCG Entertainment bought remnants of Telltale's assets and re-launched the company in August 2019. Some games are "saved", while others remain unavailable.
The new company has no prior relation to old Telltale, and thus has no obligation towards settling old Telltale's debts and responsibilities. In a move that has received mixed receptions, LCG Entertainment has only offered contract work to some past employees of old Telltale. Clearly, they are trying to keep operational costs down, while it establishes itself.