I understand Melo's point but I find it hard to believe considering that Jokic himself made it known that growing up Melo was his favorite player and the reason why he came into the league wearing #15 but also due to jersey size issues in his native country.
Now it's possible considering that Jokic was a second-round pick, that the Nuggets organization did not envision Nikola becoming the player he's become today (none of us did, and anybody who says they did is lying) so him wearing #15 at the time probably didn't mean much or matter to the organization because their expectations of Jokic was probably low at the time for the first few seasons and didn't see him lasting long on the roster going forward.
I would say Melo's relationship with Denver is similar to LeBron's when he left Cleveland and everybody from the organization to the city had a lot of disdain for him but the difference is that Cleveland was louder and much more vulgar with their animosity (burning jersey, angry hate letters by the owner, etc) whereas Denver (fans and management) on the other hand have been much quieter but the feeling/reception is the same.