Jag tror inte att det är svarat i canon, men jag skulle bli förvånad om Tom Riddle hade varit en del av tabu. Voldemort hade visat många gånger att han inte vill ha sitt Tom Riddle arv att vara känd för. Att sätta sitt riktiga namn på samma nivå som "Voldemort" skulle effektivt erkänna sin historia som han länge döljer.

Förutom vad dlanod sa, fanns det inte några människor som levde vid tiden för Dödliga Hallows som troligen skulle använda namnet "Tom Riddle" i första hand - Dumbledore var död. Så varför slösa magisk energi på värdelös extra ansträngning?

Det var nästan säkert inte.

Den mörka lorden skedde Tom Riddles namn så snart det var möjligt för honom att göra det, och även när han var ung, det var Lord Voldemorts namn som han förväntade sig att trollkarlarna skulle frukta.

“TOM MARVOLO RIDDLE

Then he waved the wand once, and the letters of his name re-arranged themselves:

I AM LORD VOLDEMORT

‘You see?’ he whispered. ‘It was a name I was already using at Hogwarts, to my most intimate friends only, of course. You think I was going to use my filthy Muggle father’s name for ever? I, in whose veins runs the blood of Salazar Slytherin himself, through my mother’s side? I, keep the name of a foul, common Muggle, who abandoned me even before I was born, just because he found out his wife was a witch? No, Harry. I fashioned myself a new name, a name I knew wizards everywhere would one day fear to speak, when I had become the greatest sorcerer in the world!”
- Harry Potter and the Chamber of Secrets, Chapter 17 (The Heir of Slytherin)

Så snart han kunde, kasta han sitt gamla namn och senare återuppstod i trollkarlen som Lord Voldemort.

“There he showed his contempt for anything that tied him to other people, anything that made him ordinary. Even then, he wished to be different, separate, notorious. He shed his name, as you know, within a few short years of that conversation and created the mask of “Lord Voldemort” behind which he has been hidden for so long.”
- Harry Potter and the Half-Blood Prince, Chapter 13 (The Secret Riddle)

När Tom Riddle försvann, hördes ingenting mer av honom av majoriteten av den trolldomslösa världen som inte kände till sitt nya namn.

“But before they were sure beyond doubt that the cup and the locket were both gone, the assistant who had worked at Borgin and Burkes, the young man who had visited Hepzibah so regularly and charmed her so well, had resigned his post and vanished. His superiors had no idea where he had gone; they were as surprised as anyone at his disappearance. And that was the last that was seen or heard of Tom Riddle for a very long time.”
- Harry Potter and the Half-Blood Prince, Chapter 20 (Lord Voldemort’s Request)

Efter att ha dödat sitt gamla namn skulle den mörka herren inte ha ansett namnet "Tom Riddle" som är värd att inkludera tabu. Han lämnade det namnet och identiteten bakom honom långt innan då.