Happy birthday,
Lauri!
Oh, and
Is it a celebration? - Yep!
Did Bilbo once celebrate this occasion in Lake Town? - Almost, but not quite IIRC (wasn't it his 50th?)
Was it as joyous as the reunion of Sam and Bill the Pony? - Hm, hard to tell, but it was joyous indeed (not least because my wife and aunt-in-law conspired to buy me a boxed 3-vol set of
The Hobbit and Rateliff's
History - yummy!); so make that a Yes!