The nearest hospital to me used to have that same 4413(29ee)sign.
I have the time, being retired from working in a law office for 25 years, to not worry about "their intent"
All hospitals were/are required to post "a sign"
Some owned by the same group as the one nearest me, ... in other cities, post valid 30.06 signs
The hospital nearest me which used to have the old sign [posted, has now removed that sign, but not posted a 30.06 sign ... instead they posted THE sign which hospitals are required to post.
If we're playing read the intent/mind of the hospital, their obvious intent was to comply with the law in posting the particular 51% type sign they are legally required to post, while knowing that doesn't affect licensees.... else they'd post both signs since they removed one, "studied up" and ordered a new sign which complied with what they are required to post.
Texas had "blue laws" where it was a criminal offense to purchase fastening hardware on a Sunday (with exceptions as it's for a coffin/funeral etc) I can't see that anyone would be arrested now for buying hardware on a Sunday.... that law was repealed.
Texas had an anti-sodomy law ... it was repealed .... while some might like to arrest someone for violating a repealed law ... I think they'd have more sense than to subject themselves to a Federal lawsuit for an arrest for something which is not illegal ... which can't be held to be a "good faith" arrest, but is a violation of civil rights under Federal law.
It is not illegal to ignore that sign, unless you are in fact possessing a handgun under 4413(29ee) which is an impossibility at this point in time. If I was arrested for something which is not illegal, I'd be looking to make some money from the settlement I'd get...
Don't ignore purple paint though, under 30.05 Purple paint is valid enforceable notice under an existing (not repealed) law
That's my retired layman's opinion, IANAL