Wrong, the US threatened to destroy Galileo if Galileo was used in an attack against the US. The threat was not China specific and its intent was to force the Europeans to use seperate frequencies for civilian and military .US Congress has withdrawn funding for projects that destroy satellites in space (due to debris). Since then the focus has been on in-theatre temporary reversible denial of service. So if the US wants to deny Iran the use of Chinese space based assets it will use ground based Counter Communications Systems that became operational in 2004. CCS uses ground based jammers for in theater denial causing no damage or loss of service to other users of the system.
The US battle effectiveness or the effectiveness of JDAM and precision munitions will not be degraded by loss of MEO GPS satellite constellation. Plan B involves the use of interoperable systems that belong to our allies, Plan C involves the use of hundreds of commercial LEO satellites. Plan D involves ORS launch of satellites by ICBM (MinuteMan missiles). Plan E involves the re-activation of LORAN systems that still cover most of the world. Plan F deployment of LOCATA that has been in exclusive use in White Sand AFB for several years.Of course if all goes to $hit we always have autonomous precision inertial navigation system such as PINS and TIMU drift corrected by PTAN that use digital terrain elevation data (DTED).
I'm too lazy to provide citations for the above but you can google LOCATA, DARPA PINS,TIMU and Honeywell PTAN.
None of the backup you cite will have the accuracy that GPS constellation provided. I do know TERCOM and laser guided ammunition can still be used. But those things have their limitation. Mid course update for any program system will still need the GPS signal for final precise location.
As for Galileo, its a very clear signal from US that they target it at China with that message. They threaten European partner to cut off signal for China in case of military usage against US interest if not destruction of Galileo.