The whole thing seemed to me a way to prevent you from getting the ones you don't want, and not just a way to ensure you get your cake and eat it in year one. Their current implementation gives you the same likelihood of finding and starting your chosen Precursor, without adding the odds of the other 6 on top and giving them to your favourite.
Before you had a 1/7 chance of finding your choice, now you have the same 1/7 but the other 6 are prevented from rolling and blocking you out; your suggestion would be for this new feature to just give you a 7/7(discounting Systems that spawn without tags) chance of finding what you want, and making it 7 times faster on average.
I kind of agree with their implementation, in that selecting less than the total should not improve your odds of getting what you want, only reduce the odds of getting what you don't want.