Just visited a website, which at the top of every page "Please paste your Google Webmaster Tools verification here"

What's odd, is this isn't a way I've seen to verify. Some kind of odd scam? 🤔

Wtf has happened to Google webmaster tools / ad(word)s / analytics? There used to be so many valuable insights before the current version, now everything is hidden in the new UI or Google just keep the info to themselves? Does anybody use Google anal/ads anymore?

To anyone that can give me advice
I have my main business website,made in WordPress,with all my content.i used Google webmaster tools to request indexing for all the links on my website.i want to change from WordPress to less annoying CMs which is light and fast or I'm even considering using Django.if I build my site again ,and request indexing for all links on my domain
What happens to the old links.and will my new links get indexed?