The 1999 bubble was only an issue because it happened with publicly traded companies that lots of people were investing in and making unrealistic gains on. You couldn't watch television without seeing ads for online brokers showing how easy it was to get rich quick, and your "My Account" page on said brokerage site was eager to tell you about your 10X margin and encourage you to use it. When it popped, all those stock portfolios went back to where they started (or worse), and hilarity ensued.
This time around, there's none of that. The "Bubble" is simply a handful of private companies getting silly valuations. If that stops happening, there's really no aspect of it that will bankrupt your random average family in the Midwest.
So yeah, sure, call it a bubble if you'd like. But it seems from here to be a harmless one floating off in the distance rather than a 1999-style one that we were all living on top of.