Upgrade SQL Server 2014 AG to SQL Server 2017 AG
As per the msdn link here, the answer is very much or possibly yes. I have not tried this out so I cannot assure that it's 100 percent will work out. It suggest that if you have a test environment go ahead and setup scenario like this and give it a shot. I is Just like how mirroring works, it's expected to be same or similar to logshipping. But make sure that the secondary is not readable as the secondary replica will be in higher SQL Server version .