I hope it's not the Groupon story repeating, where they went from funky-accounting to GAAP and all numbers had to be re-reported, obviously not in the company's favor.
It's not like Groupon. EBITDA is a totally normal metric to get a sense of how the core business is doing, and positive EBITDA in tech is a good leading indicator of profitability.
EBITDA is basically "how profitable would the business be if they had no debt and their existing assets never lost value?". For companies with factories, airplanes, etc. the physical plant deterioration matters a lot. For biotech companies with patents that expire after 20 years, asset value loss matters a lot too. But tech companies have neither physical capital nor TTL'ed intellectual property, so EBITDA is a good approximation.
What happened here is that the whole travel industry is falling apart, not accounting gimmicks.