The Indus water will continue to flow due to gravity to Pakistan, since India has no storage structures on its tributaries Jhelum, Indus and Chenab to prevent the flow to downstream.
In nutshell, freezing a treaty doesn't alter gravity flow 😎
Understand Indus System
6 rivers of the Indus system into ‘eastern’ and ‘western’ rivers.
Sutlej, Beas and Ravi are eastern; Jhelum, Chenab and Indus itself are western.
Under IWT, India got share of Eastern rivers (33 maf) while Pakistan got Western Rivers share (133 maf).
Do we have a switch to turn off the flow to Pakistan? Zilch