They couldn't have meant THAT

The fact that legislatures did not regulate firearms in exactly the same way as they later did at those parks doesn't mean that they believed that they couldn’t do so constitutionally. And the fact that starting with the opening of Central Park, the prototypical recreational park in 1859, I believe by 1861 Central Park then enacted a set of rules that lasted I believe until today, though I could be wrong about that, but certainly for a long time. And every park that followed, including here in Philadelphia at Fairmount Park, in Pittsburgh and everywhere else, including the national parks, all then enacted the same restriction on carrying firearms.

I think for plaintiffs to be right, you would have to think that that is not a historical tradition that Bruen would have recognized. And I think that is impossible to square with what Bruen told us about the need to identify historical precursors and to assess whether or not our forefathers would have thought those precursors were permissible under the Second Amendment. [xCite item="T2EL2LW8" p="12-13" pos=0]

Translation, since Bruen said that

the government must demonstrate that the regulation is consistent with this Nation's historical tradition of firearm regulations

[xCite item="75DAVPP7" pos=1] that there must be some regulations from that time that would be acceptable under Bruen

This argument has been made many times. "If Bruen means what Bruen says, there are no modern infringements that would stand. Since the Supreme Court presumed that some infringements are constitutional, or that they were not addressing questions regarding those other infringements, then Bruen can't mean what it says."

"No true scotsman..."