To question WhatsApp group on personal phone for work?

[Diedre44]

WFH permanently small team Customer Service for local government housing association. Got an email from manager today stating for business continuity and case of emergency everyone needs to be contactable and if don't already have it please download WhatsApp and let us know when you have so we can create a WhatsApp group.
I'm just confused as to why we are being "told" to do something on our own personal phones. I do not use my personal phone for work. I am contactable by telephone, I'm available on teams whilst working, email etc.
My manager knows I have WhatsApp already, we speak outside of work on occasion. I just find this strange all of a sudden.
I don't know how to approach it with them as don't want to seem to have an issue. Surely if it is needed as a "needs of business" issue they should provide a work phone.
AIBU to be sceptical?

But HR and your boss have your contact details so if there is an emergency they can text or phone you. That’s fine. But a WhatsApp group means they’re expecting you to install an app (OK, one most people already have but the principle of it), and more significantly, make your phone number available to anyone they decide to add to the group.

Ok I accept that. I have seen it from the other side where we have had to contact all of our reports out of hours due to terrorist attacks (we had a policy checking on everyone who might have been in the vicinity) and it took ages, looking up almost 40 people's personal mobile numbers and contacting each individually. But people have a right not to have their personal phone numbers made available to others if they don't want to.

We have one on our personal phones as not everyone has a work mobile. It's only used for business continuity although people working at home occasionally post to say their broadband has gone down and that sort of thing. No one abuses it as the purpose was made clear at the outset and I hardly get any messages. I've got the option of muting or leaving if I get fed up with it.

In our firm, there was a cascade as someone mentioned above. So the text went to the directors, who sent it to the senior managers that report to them, who sent it to their direct reports, who sent it to their teams and so on. How well that works depends on the size of the business and the hierarchy I guess - sounds like it wouldn’t work as well in your place. But as a general thing, all businesses should have some type of contingency plan in place, one that doesn’t depend on WhatsApp groups on personal phones.

It depends what their intentions are.

If it's for one off emergency messages once in a blue moon that you would actually be grateful to receive then I can't get worked up about it. Such as if the phone lines are down, server is down etc and instructions on what to do or to keep you updated.

If they are going to be firing messages left right and centre about things that aren't important and could be sent via work email or teams then I'd just be honest and say you prefer to keep work and personal completely separate and would prefer communication vis official work channels.

You can hide your online status too if you wanted to switch it off during working hours so nobody can see if you are online.