Could this be fasciation as described in a post not so long ago? My neighbors plumeria tree has a fasciated tip that I see now that I know what it is... It has an inflo but is trying to make like ten tips or something weird like that... I'm going to keep an eye on it since its a vigorous grower and should pan out to something or nothing within a month or two....

Here's a photo... I broke some leaves off for a clearer view (no worries, the tree is massive and grows fast) but the tiny tips are not in a row like yours. Normally this tree likes to put out 3-5 tips per inflo, but this tip is big and flat... Waiting to see what it does. The branch is over my property line and will be lopped off and composted or given away in the fall... But until then its like a science experiment...

Yes, I think it is just that...wonder/wait if it blooms....roxanne