The spelling of the word, much like any and all words, changes based on how it is used by the people. Standards and definitions follow the usage. It’s not about debate, that’s literally just language. You can already see this reflected in many sources, such as Wikipedia here:
The English spelling and even names for certain SI units, prefixes and non-SI units depend on the variety of English used. US English uses the spelling deka-, meter, and liter, and International English uses deca-, metre, and litre. The name of the unit whose symbol is t and which is defined by 1 t = 103 kg is ‘metric ton’ in US English and ‘tonne’ in International English.[4]: iii
The spelling of the word, much like any and all words, changes based on how it is used by the people. Standards and definitions follow the usage. It’s not about debate, that’s literally just language. You can already see this reflected in many sources, such as Wikipedia here:
https://en.wikipedia.org/wiki/International_System_of_Units#Unit_names
or here:
https://en.wikipedia.org/wiki/Litre