July 1 is Somalian independence day which is the date on the tweet there, looks like the person saying they were going to put the flag up was wrong, lying on purpose or not I can't see.
But if they wished a happy independence day to them on the independence day of Somalia it's not really anything to get bent out of shape about, if there's a large population in the area it's nice to give them a wave.
We do it for lots of other groups after all.
Just for funzies though someone should do Somaliland's independence day too, because Somalia gets mad when you mention Somaliland.