Unless you have access to the detailed training plan it's kind of meaningless to discuss around "only taking a week off", because "a week off" can mean countless of different things.
A week is a long time for professional athletes today. If it's a week completely off the bike it could even be a too long period. If it's a week with quite a bit of training but it's all just at low intensity it might be too short period.
In the end, as long as the information we have is vague like "a week off" it's impossible for us to have useful discussions around it.
In the context of (to) many competition days and always little rest in between, and the disappointing result in Switzerland (not fresh anymore), is only a week of rest after Switzerland very relevant. Too little rest!
A top rider who wants results and peaks twice or thrice during the season must take at least two longer rest periods. During the season. This is not about someone acting as a domestique. Or Thomas Degendt who does races the season round, so that he rarely achieves results (not in proportion to his qualities ).
An altitude trainingcamp may be less grueling than competitions, and certainly than stage races. But if Evenepoel doesn't start it well rested, he will also start groping in his reserves. Canceling Burgos won't change that much