They obviously know what kind of pre-order numbers their games usually get and can base estimates about market interest on those. If pre-order numbers show that there currently isn't enough of a demand for your title, then... you've got a problem.
If they just need a stupid excuse, then I'm sure there are a dozen better ways than saying "Our product is about to become an absolute financial failure", considering that this doesn't exactly build up faith in your product.
Preorders have decreased compared to past, we have a clearly example from COMG, one reason might be nowadays games come out incomplete, bugged, with less contents (who said SFV ?
), at the same time if you take look at current system charts and compare them with previous generations you will see how tie-ratio has decreased, especially for sony platforms, cause nintendo games always sold in the long run.
This could mean that now people wait for the game to be released, check on internet about impressions, word of mouth and so on.
But probably the main problem for Uppers, for a game made by Marvelous is the lack of the boobs, even if they add something (and honestly that part in the game is the one I didn't like and felt as forced to attract some buyers).
So if they want to make a game but they don't know so well how could be the potential sales just make a Kickstarter and see what happens, but I'm asking too much for a japanese company...