Will the Data table Widget and the "Add Cells" Menu come back for version 2

The short answer is no. The longer answer is that there are forthcoming improvements that will provide related functionality with significantly more capabilities.

I discuss the rationale for removing the add cell menu and data table cells here, along with the role of AI for synthesizing common code snippets:

The forthcoming improvements to SQL cells should address much of the functionality previously provided by data table cell, including visual summaries with interactive filtering, but the SQL cell is much more expressive (since you can write SQL) and therefore less of a “dead end”.