Did you read the article? It starts with "London's startup scene is booming -- you need only read Wired to see that. But what are Europe's other hot digital cities -- and which are the companies and founders to watch?" - so it's about what else besides London there is. Not downplaying London at all.
It's quite cold in London at the moment (17°C).
Probably omitted on purpose for reasons unknown.
Likely because its a UK website - showing cities on mainland Europe.
...so it's "top 10 locations I'd rather be right now"?