t͡ɬ is a phoneme in Nahuatl [0] (Voiceless alveolar lateral affricate [1] if you care to hear it), which explains why many Nahuatl words have sequences of "tl". I don't know if there's a specific reason why these words end with that sound (it doesn't have to be a suffix).

Edit: yes, it's a suffix (for Classical Nahuatl): "Non-possessed nouns take a suffix called the absolutive. This suffix takes the form -tl after vowels (ā-tl, "water") and -tli after consonants [...]" ([2]).

0: https://en.wikipedia.org/wiki/Nahuatl#Phonology

1:https://en.wikipedia.org/wiki/Voiceless_alveolar_lateral_aff...

2: https://en.wikipedia.org/wiki/Classical_Nahuatl_grammar

> Is it required for Nahuatl nouns, like the Latin -t suffix?

I don't understand what you're thinking of here? Here are some Latin nouns, all in nominative case:

    nauta   (first declension)
    puer    (second)
    gladius (second)
    malum   (second)
    lex     (third)
    limen   (third)
    tempus  (third)
    virtus  (third)
    civitas (third)
    cornu   (fourth)
    manus   (fourth)
    res     (fifth)

I gave the nominative case, but in fact none of those nouns has any form ending in -t. The only -t suffix I know of in Latin is for third-person singular verbs.

Ah, sorry, yes, I meant the verbs. Originally I was going to make a comparison to nouns—nouns in Lojban, which have a -j suffix.

I'm confused and am not sure if you're thinking of something else or if I'm quite misinformed about Lojban. I don't think lojban has suffixes at all (prefixes, on the other hand). For -j specifically, the only words in lojban which are permitted to end in j are names, but there it's not obligatory. Names are required to end in a consonant, but there are at least a few that are more common than j, I think.

FWIW `-j` is the plural suffix for all nouns and adjectives in Esperanto (not in accusative where the full generic form followed by an additional `-n`), but I don't know whether the OP had that in mind or something completely different.