I honestly think the world divides into those who think "Why would I?" and those who think "I must" or "Why wouldn't you?" We've had endless issues with this over several decades with a family member who falls into the latter category. The rest of us are more inclined to think that you'll be contacted if needed. When I took my children to PGL holidays I never phoned, and they would have thought me an embarrassing fusspot if I had done. When family members have been in hospital (unless severely ill) I would not visit or phone every day.
Other people have different emotional needs and feel compelled to stay in touch, or maybe don't trust the professionals. I don't know. Sometimes they are right to be suspicious and pester those caring for their friend / relative, so I would never say don't do it, because sometimes your instincts tell you something that your mind has not processed. However, if you trust the facility and know that your loved one is being well looked after, you should allow yourself to detach.
This is the greatest benefit of respite, that mental detachment from responsibility for a vulnerable person. Some people feel unbearably guilty and can't allow themselves to detach as if it is abandoning the person they care for. You sound as if you have a very healthy attitude to this respite break.
I think the issue with other people poking their long nebs into the situation is that they don't like change from the status quo. You have made a change, albeit temporary, and they feel compelled to try to put you back in your box. I agree with Grannie G, my response would be "No I haven't. Have you?" "No? Well feel free to let the CH know that her friends are thinking of her. I'm sure we'll speak again after we've had our respite break. Just for now we're having a well-earned rest. Thanks for calling, goodbye."