According to ESRI, support for the JS API 3.42 will end in 2024. WAB is based on this JS API 3.42.
https://support.esri.com/en/products/developers/web-apis/arcgis-api-for-javascript
Does it means that WAB will be obsolete, despite the repeated assurances from ESRI that WAB will be supported?
I heard someone say to a lawyer, "forever" means about 30 years.
With Esri, my observation is that when Jack announces a new product he always makes it sound like you can use the old product forever but generally "forever" here seems to mean 3-5 more years.
Agreed. It happened before when they announced WAB but they said that Adobe Flex was going to stay.