Yes, it's a deliberate policy to force you to engage with a sales agent who will try to upsell you a bigger/more expensive package. The message to 'call the team' is often an alternative to the ever-unpopular 'oops something's gone wrong' message.
In all likelihood though, any generic renewal offer you get from VM is unlikely to be very good value. In addition we have seen endless topics on here recently where a renewal offer claiming to keep everything 'the same' as part of a generic renewal offer turns out to be completely untrue and some services are missing from the renewed package (which forces the customer to ring up anyway).
If you wish to renew with VM, the unfortunate truth is that you are likely to be best off phoning up and having the painful renewal conversation.
Before doing that though, arm yourself with information about what competitors in your area can offer. VM's offers on the phone are 'of the moment' so you need to be armed with other prices before phoning in to decide whether to accept there and then.
An alternative approach would be to put in a cancellation when you phone VM. Some have reported recently on here that was the only way to get a sensible renewal offer (although you may well have to follow through and leave if VM does not come up with something that is acceptable to you).