Considering that we're on sqlite3 already, it'd probably be something for the v4 ;)
There is already an sqlite4 but they haven't done any work with it for a long time.
This would be something on the order of the python2 -> python3 transition. Meaning, it would likely take a decade. After going though that, I'm not sure it would be worth it to just change from (default) flexible data types.