There is construction going on in Wengen as well, it’s just part of the growth process. In Wengen It’s at the top part of town, so if you stay closer to the train station you’d be fine there.
When helicopters are used for building it’s a 1 minute fly in and drop off, it’s not like you’re on a military base. In some ways it’s actually fascinating to watch. But of course not everyone finds it interesting.
They are working on the Schilthornbahn right now + the new Murren Palace Hotel near the train station and from May 6-31 the train to get to Murren is closed for them to put in the new train cars, so if you’re staying between those dates your way to get to Murren is Lauterbrunnen > Bus to Stechelberg > Cable car to Gimmelwald > Cable car to Murren. So you may not love that additional bus connection.
Where is your hotel in Murren?