As an ex 101 and 999 operator I can categorically answer this.
The operator will usually be a civilian not a sworn officer. They can look on PNC to see if you are wanted, but would normally just look on their local systems, unless they can see a glaring "wanted on warrant by another force" especially if your name/ phone number is already known to them to check you were not wanted for a serious crime, even if you were they WOULD NOT tell you, they would simply alert the officer/ station looking for you, depending on the seriousness of the alleged crime. The reason for this is as exactly described I could for example give Name, date of birth and home address of a friend of mine and the person on the phone who talks to 30-50 people A DAY, over a 10 hour shift would not know I was not my friend. The operator (call taker) would then be in breach of GDPR, with potentially very large fines for them and or the police service, not even to say operationally difficult, as generally if a person is thought they are wanted they go to ground or disappear and normally has a reason to think they may be, either they have gotten away with something or think that an officer may be looking for them. Even if an officer comes to your address and you are not there they will simply ask the person who answered the door to confirm their identity and ask you to contact them be this for an arranged voluntary interview or arrest by appointment. Most arrests are by appointment these days, so there is minimal waiting around for duty solicitors, this has the advantage of less waisted custody time for you and longer for them to get evidence to prove or disprove your involvement.
The same goes for a "missing person" who you believe to be in Custody, if they are an adult they have a chance to make a phone call to another adult to let them know they are in custody, unless it is operationally prudent to keep the person "incommunicado" , ie a person may destroy evidence or if they are wanted for this or similar crime they again may go "missing themselves". They will ask you what efforts have you made to find them, ie have you called them, gone to their address, contacted the local a&e, when did you last speak to them or how often do you speak to them, Do they have any special needs that make them more vulnerable. If they are in custody they may tell you "we have no concerns for their safety", it generally means they are in Custody or we have contacted them and they have assured our officers they are safe. They are trying to get you to read between the lines. Do not keep asking can you tell me if they are in Custody or the reply you will get will sound like a broken record, I cannot tell you as they are an adult and would have a right to contact a person . We do however have no concerns at this time. (a child/ person with obvious learning difficulties or ability to communicate is slightly different, but they would need to be convinced that the person is the child's parent/ guardian and normally this would either be a check from a known phone number ringing in or the custody sergeant would make the decision if they wanted to speak to you.)