What-if events are stored as properties in internal model-scenario tables.
Unfortunately, what-if events info cannot be extracted by a simple query as you can for Reservations and there is no Public View for that.
Just as reference, you can see with this SQL query how this info is stored in the database:
select * from PR_TC_PROPS where name like 'tc.event.%' order by tcid, name
Please note that table PR_TC_PROPS (that contains the properties for each model scenario) is used internally by the product, so it could change in future and there is no official support for that.
Hope it helps,
Thanks Gaspare, useful to know.
Not sure what to do with that knowledge now, but will add it to the bucket of "Things you might need to know"...:)