Should Netflix be worried? Most definitely.
Not only is it heavily in debt from trying to produce its own content (a lot of it that I've been disappointed at), but Disney+ is going to start at $6.99/mo with 4K content -- compared to Netflix's $13/mo HD-only or $16/mo 4K-included pricing.
For the price of a Netflix 4K subscription, I could get Disney+ and add Hulu at $5.99/mo. And with both, I will still be saving $3/mo.
Netflix should be worried.