Backing you up with some more sources: Webster's 1828 dictionary [1], which the grandparent cited, does not have the "make regular" definition, but rather definitions consistent with modern usage:
>1. To adjust by rule, method or established mode; as, to regulate weights and measures; to regulate the assize of bread; to regulate our moral conduct by the laws of God and of society; to regulate our manners by the customary forms.
>2. To put in good order; as, to regulate the disordered state of a nation or its finances.
>3. To subject to rules or restrictions; as, to regulate trade; to regulate diet.
Samuel Johnson's 1755 dictionary [2] has much briefer definitions, but also defines regulate in an interventionist, controlling sense:
>1. To adjust by rule or method.
>2. To direct.
There is absolutely no basis for the claim that "regulate" used to mean something like the opposite of what it now means.
[1] https://webstersdictionary1828.com/Dictionary/regulate
[2] https://johnsonsdictionaryonline.com/views/search.php?term=r...
I've seen this rhetoric used somewhat frequently by 2A advocates but it's completely bogus. The word has had the same common meaning in English since at least the early 1600s.[1] Even in Latin the word regula (from which "regulate" originated) was used in the context of governing, control and regulation as we know it today. As in regulae iuris which was literally, the regulation of interpreting the law.[2]
I've yet to see anyone present any argument at all, let alone a reasonable one, that would even form the basis of such a theory for the "changed" meaning. It's always just stated as a fact when, in fact, it seems to be a completely fabricated talking point.
[1]https://www.etymonline.com/word/regulate
[2]https://en.wikipedia.org/wiki/Regulæ_Juris