We all knew that, 2018 model has the same design, however thechnically Y chips are designed to run fanless, I had a M3 Y30 from intel which is almost the same chip as new MBA and didnt have any fan either and never had any problem. Of course I didnt expect amazing performance.
The fact is MBA chips are underpowered but they aim to consumers which use their computers for web browsing, netflix, office word, excel etc.