How "private" is the new private networking?

Hi All, I am quite unexperienced in networks so I would like to ask someone who has more knowledge on this topic.

When DO introduced private networking back then there were some criticism that communication through the private network is not private at all while others can intercept the traffic within the same network (datacenter). So if you wanted to use the private network securely you had to configure a VPN for example to encrypt the communication.

Now I saw the announcement stating: “As of July 18, 2018, DigitalOcean private networking isolates communication at the account or team level between Droplets located in the same datacenter region.” and I was wondering whether this means that configuring a VPN is no longer necessary or others still have to possibility to sniff or even modify my traffic? I have searched DO support and other resources on the internet but I haven’t been able to find any reliable answer for this question.

It would be very nice if DO could clarify this, while misusing the private network could bring a huge security risk which could really bite unexperienced users like me.

Thank you very much for your help in advance!