Re: "there was no specific policy in place directly for WhatsApp"
>” Staff used WhatsApp. That means that that was the easiest solution.”
WhatsApp and Zoom were the two solutions to hand back at the start of lockdown; need to remember the time pressure and supply constraints when he first lockdown was announced; basically, whatever remote working solution you needed had to be doable on the equipment you had deployed and could reasonable expect people to already have.
Yes there were alternatives to WhasApp and Zoom such as Signal and Jitsi, not forgetting WebEx et al. However, as noted MPs were using these mainstream products so I expect many heard the media stories and “ if it’s good enough for them….”
Fundamentally, this is a collective failure in business continuity planning etc. - however, unless you had been involved with say the IRA bombings in he city of London, who would of planned for workers having to suddenly work from alternative venues such as their home? But even then I suspect no one really considered it happening to everyone at the same time.
In some respects it is noteworthy that the Cabinet Office kept so quiet over both the technologies government and its agencies should be using and how to make them secure.