They pulled out citing the F-35 was given undue favours. This was the reason given by Dassault as well.
You see, you claimed "long term operational support". Both Dassault and Boeing are capable of providing exactly that. For example, the maintenance contract signed with India is for 50 years. Both aircraft offerings have proven capability of having received long term operational support, the F-35 has not.
What's more? Belgium also asked for assistance from support assets of the country's respective air forces. The US and France are naturally capable of providing this support.
https://www.airrecognition.com/inde...id-for-belgian-f-16s-replacement-program.html
Basically, the Belgians are better off going through a direct FMS contract instead of the tender farce. Gripen, Rafale and SH are out of the race.