No. The "fixed minimum 10%" (or lower on big routes) is only shown if nobody is flying on the route on that travel/cargo class. If one starts to fly that route, the actual demand will be calculated based on what you offer there and it can be less than the 10% too, or it can grow higher over time etc.
For the first few game weeks you have (sort of) no risk of demand falling (due to calculations being performed at a slow/gradual pace) but that is the entire idea of the minimum shown demand! As if all demand would shift to the other airport the whole city demand and shifting between airports would be a moot point since nobody would be able to start at the secondary airport if all demand is shown as zero.
(And also yes the border crossing rule set is not active yet.)
This is solving a problem that does not exist.
For all practical purposes (considering the strong influence of RI on cargo routes), the amount of cargo picked up in first for months by the airline rounds to zero. And since the demand shifting (based on my observation) seems to be a function of supply, not of the amount currently flown, in the first 4 months, just about all of the shift has already takes place. The pace of demand shifting is now very swift, all of it happens before the high RI kicks in and player starts delivering cargo. Problem solved - or no problem existed in the first place.
So the stated purpose of the minimums is effectively eliminated. What remains is all negative
- freeloading - flying un-economical routes at unearned, artificial, system guaranteed minimums (just about all of the route pairs between NYC, LA, London are there, so no CBD in places where it was supposed to work the best)
- leaching all of the demand from economical routes - no RW equivalent of dedicated cargo demand between secondary and tertiary airport (except specialized hubs, like Memphis, Louisville, Leipzig)
- fragmenting of the demand to the tiniest component - which has no RW equivalent
- destroying Very Large cargo Aircraft as a viable strategy - unlike RW, where cargo airlines are now searching the deserts for 747 that could be converted to cargo
Showing potential demand as zero is very useful information. It means that all of the demand is being served by other airports, and any of the demand shifted will have to be earned, by taking it from other airports. (There is no other graphics, no UI to give player this information, other than opening 25+ tabs with all the combinations of route pairs to provide this info. The minimum actually misleads the player into thinking there is some unserved demand, while there may be none).
Hopefully, low starting infra and traffic numbers, reworking of infrastructure to make number of different categories (cargo, pax, runway, transportation)and levels that have to be earned / unlocked, some airports will develop while others will not - which I think was the original intention of CBD.