Will a different Vodafone broadband & voice package break my monitored alarm system setup?

I had to query an item on my landline broadband and voice bill (Vodafone), and the agent offered "a cheaper package with everything the same".

But when the fine print email arrived, it included this:

"...If broadband and voice:

You can make and receive calls on your home phone using broadband voice

technology. Some services such as monitored alarm systems, fax machines etc.

which worked through traditional landline functionality will no longer work with this

service."

My alarm system is a GE Simon 3, exEircom Phonewatch from 2008 but monitored for years now by another company, still doing all we want.

Does the fine print from Vodafone mean that switching to the "cheaper" package will break this monitoring setup? (it certainly seems to say that!)

Can I avoid that by cancelling the package switch within the cooling-off period, or was the landline monitoring going to get broken anyway in the near future?

Any advice welcome!