This exactly.
Though I still wonder what idiot at the FIA thought settling was a good idea. If they couldn't have proven that Ferrari cheated, rule the car legal and add the extra sensor for this year. This surely would have been a better outcome than this detritus show of people and other teams being up in arms over secret settlements and the FIA still not having actually said Ferrari were legal. Yes, innocent until proven guilty so we must treat Ferrari as innocent but I think it says a lot that the FIA have only said they couldn't prove cheating rather than actually say they're innocent.
Which is exactly why there was a settlement.
Exactly as MissChief said
FIA ‘We know you’re cheating, we just can’t prove it. We’d rather not spent months and millions of pounds proving this, please stop cheating. We won’t take it any further and you won’t be punished with points reduction or fines’
Ferrari ‘Seems fair. We’ll stop what we were doing. This is not an admittance of guilt or that we were cheating though’
It's far simpler to get Ferrari to stop what they were doing via a settlement, than declare the car legal, make it very public and have all teams spend millions trying to copy the same thing for just one year.
the whole pint of the new rules next year is to reduce costs, not make teams spend even more trying to emulate what one team found.
As no doubt like DAS next year either the rules will most likely prohibit whatever was going on any way, or even more likely the FIA will fit their extra sensor to all cars next year.