As an avid Crickets fan over the decades I can tell you that Pakistani support was very passionate in the 70's 80's and 90's and we turned up in bigger numbers than the Indians for cricket matches in the UAE and England.
However, WC 1999 was the last time that Pakistanis outnumbered Indians at a cricket match in England. The Bharat Army was formed and coupled with corporate skills they formed associate companies and have now become influential ICC event Ticketing partners. This together with the heightened religious like Zest and demand to watch 'Superstar' Indian Cricketers is the perfect storm that results in what we have been seeing in Indian ODI matches for the last Two decades.
For me the 2004 ICC champions Trophy match In Birmingham between India and Pakistan was a shock to the system, when around 85% of the Crowd was Indian and it felt really strange to be heavily outnumbered.
The reality is that for this 2019 encounter, only around 12,000 tickets were actually available to ‘scrap’ for online to the general public, and the majority of the remaining tickets were in the control of Indian based ICC Ticketing Partners and corporates.
https://www.bbc.co.uk/sport/cricket/45464635