I'm planning on visting Switzerland for the first week of September. When I came in the pre-covid year of 2016 most places to stay and things to do were still open. I'm wondering if any places might be closing the summer season earlier this year? In the research i've been doing I have not seen any mention of changes on any of the websites i've vistited. I wonder with the rapid changing covid situation if everything is up to date.

My plans right now are to go to the Berner Oberland and then finish up with Ebenalp/Schäfler.

Well, as far as I know most places which are still in business will remain open with normal operating hours, but it's definitely worth checking/booking directly - since there have been a larger than usual number of business in the hospitality industry which went bankrupt over the last year, the supply has diminished. However, with international travel tricky for many/most people, demand is also down ...
Summer this year has been mostly wet, as you might have heard ... even floods in some parts of the country (and surrounding countries), but hopefully this will clear up by September to give us a sunny end to summer.