Ah dammit, I want to write something.
It was agreed that to declare Bilbo legally dead without a body would require the Mayor of Hobbiton, the Master of Buckland, and the Thain, to all sign off on it. It wasn’t couched in law, but Everyone Had Decided.
Which means it reaches the point where the three Hobbits required to agree on Bilbo’s death are the same three who witnessed him sailing to the Undying Lands. Now, he’s technically not dead, no, but he’s not coming back…probably.
Sam, Merry and Pippin put their heads together and create a new status, Departed and Most Unlikely to Return (Most Unlikely for short). In keeping with what Everyone Had Decided previously, it requires the sign-off of the Mayor, Master and Thain. Sam put forward that a former holder of the offices should qualify in place of the incumbent, and while at first Merry and Pippin merely shrugged and agreed, they later remembered the idle moments Sam would stare westwards. The new legal status was accepted, and both Bilbo and Frodo were declared Most Unlikely.
Decades pass, until Rosie Gamgee, née Cotton, dies. Sam stares westward a lot more after that, and it’s not long before he brings Merry and Pippin the papers to have himself declared Most Unlikely. He’s already signed in place of the Mayor, to take effect in several months. Merry and Pippin agree to sign when the time is right. A few weeks later, Sam’s eldest daughter Eleanor visits to inform them her father has departed. They sign.
Merry and Pippin themselves had never thought of leaving, even as they age, until a letter arrives for Merry from King Eomer. He’s dying, and wishes to see Merry one last time. Merry discusses it with Pippin; he’s not sure he’s in good enough strength to travel to Rohan and back again. There’s no way Pippin would let him travel alone, and he’s thought of seeing Aragorn in Minas Tirith again. They’re both widowers, with children and grandchildren, and, well. They’ve already filled out the paperwork for Most Unlikely three times.
I don’t know who the Mayor is at this time, but I like to think it’s one of Sam’s sons, for the symmetry. The three sons watch the two fathers cross the border of the Shire, and sign their names to the papers.
Some years later they receive a letter from Minas Tirith, from King Elessar Telcontar himself, telling of their fathers’ passing, and the honour he had bestowed of placing them in the royal cemetery.
And it was discussed, should the status of Merry and Pippin be altered from Most Unlikely to deceased? Nothing much would change, but it would be neater, would it not?
But when they broke for lunch, they heard some children singing a skipping song:
These are the Hobbits Most Unlikely to Return,
Mad Baggins, Sad Baggins, Gamgee the Gardener,
Gondor’s Took and Rohan’s Brandybuck,
These are the Hobbits Most Unlikely to Return,
But don’t you say they’re dead, for you never can be sure,
If you say they are, they’ll come raging at the door!
And so it was decided, they would remain, Most Unlikely.