I don't think that's necessarily entirely true (simply regarding whether they're there or not) although, specific medical info is protected. I looked into this a little and found some info, but a lawyer would surely understand these things in greater depth. For instance, what defines a loved one?

From: FAQ on Access to Patient Information by Friends and Family | ACLU 2017

Q: Can I find out if my loved one is a patient at a particular hospital?

A: Generally, yes. Under the HIPAA Privacy Rule, if you ask for a loved one by name, a hospital or medical facility can usually tell you if he or she is a patient at its facility.[iii] - (iii refers to 45 CFR 164.510, see below)

There are instances, however, when a hospital or medical facility will not be able to tell you if your loved one is a patient at its facility, such as when your loved one instructs the hospital not to disclose any information about him or her, or when the hospital maintains a policy of not revealing any patient information, unless otherwise directed by the patient. (Such a policy is not required under the Privacy Rule, but has been adopted by some hospitals.)

From: Cornell Law School, Legal Information Institute web site: 45 CFR 164.510 - Uses and disclosures requiring an opportunity for the individual to agree or to object.

A covered entity may use or disclose protected health information, provided that the individual is informed in advance of the use or disclosure and has the opportunity to agree to or prohibit or restrict the use or disclosure, in accordance with the applicable requirements of this section. The covered entity may orally inform the individual of and obtain the individual's oral agreement or objection to a use or disclosure permitted by this section.

(a) Standard: Use and disclosure for facility directories -

(1) Permitted uses and disclosure. Except when an objection is expressed in accordance with paragraphs (a)(2) or (3) of this section, a covered health care provider may:

(i) Use the following protected health information to maintain a directory of individuals in its facility:

(A) The individual's name;

(B) The individual's location in the covered health care provider's facility;

(C) The individual's condition described in general terms that does not communicate specific medical information about the individual; and

(D) The individual's religious affiliation; and

(ii) Use or disclose for directory purposes such information:

(A) To members of the clergy; or

(B) Except for religious affiliation, to other persons who ask for the individual by name.