I thought this must be from Deloitte's US technology fast 500...

I thought this must be from Deloitte's US technology fast 500 list, but this year's winner is Donut Inc, so perhaps you should place a link to where you have sourced this information. This year's Australian fast 50 list which has Big TV Review in 4th place has Hireup in first place.

Here is the link to this year's technology fast 50 Australia awards from which you can download this year's report:
https://www2.deloitte.com/au/en/pag...cles/deloitte-technology-fast-50-winners.html

In the real world $1.7b trumps $650m, so your hypothesis is fanciful, unrealistic and without merit. As BIG grows, so undoubtedly will Diply who won't be waiting for any overtures by BIG when there are any number of options available to the founders and their financial backers to capitalise their company.