The protest was about whether the new team could buy and use the parts developed and used by the old team.
The Haas argument (for what little it was worth) was that the rules say two teams cannot use the same parts, and therefore 'Racing Point Force India' can not use parts used previously by 'Force India'. It is perfectly obvious the rule was NOT intended to disbar such a purchase, and meant two concurrent teams. The stewards chose to address this by saying that 'Force India' was no longer an F1 team when the parts/IP were sold, so there is no issue.
An argument that is very hypocritical considering how much help Haas have clearly received from Ferrari when it comes to designing their F1 cars.
What Haas and Ferrari did may have been legal via loopholes in the rules, but it really does not make them look good in this argument.
People like to dismiss this a conspiracy, but when was the last time you saw a genuinely new team (rather than a buyout of an existing team) better established one in their debut season?
Haas' argument is because they did not get the prize money, no one should. The problem is with this attitude nothing can be changed. The issue over Haas getting money was largely down to Ecclestone, he has now gone so things can change, or at least they should be able to.