Upvote:2
It's unlikely to have a detectable effect other than perhaps some small local markets. Thomas Cook was not all that big: they operated about 40,000 flights per year which is about 1/10 of 1% of the total number of flights that's about 40,000,000/year.
Hotel and flight pricing is heavily based on supply and demand and things like day of the week, season, special events, etc. are likely to create more daily swings in prices than all of Thomas Cook.