Best not to overthink it - The sales clerk is trained to ask for this stuff.
Luckily most times I encounter this I just tell them no I don’t have a phone number with them & continue checkout like normal. Sometimes that means not getting a sale price on something but usually I avoid those type of member-specific sales anyway.
And worst case - Just make something up. At Best Buy a sales rep absolutely refused to sell me something from the mobile dept without my info. Which didn’t make sense because earlier I had bought something at that same Best Buy with a different rep & that rep took my order without my info no problem (she said she had to enter a phone number but just entered Best Buy’s).
Yet this particular sales rep refused to proceed without info, so yeah he got an entire fictional name/address/phone/email on the spot.
The service seems kind of generic, maybe even worse than the other generic VPN services. No statements about what they log, whether they allow p2p, no mention of port forwarding, servers in only 5 countries which you may/may not want to VPN through, etc.
Not sure about the software, I guess they think it will be an improvement over OpenVPN/WireGuard which is debatable.