Is general purpose serverless tier of Azure SQL DB good choice for data warehouse database ?

What we typically do for these systems is use a DTU-based Azure SQL DB. Keep it at S2 instead of using serverless, then as part of your loading process, scale it up to whatever level is needed (only takes a minute or two), do the work, then scale it back down. Don't go below S2 though, or you will incur a full database copy when scaling.