Hello,

To answer your question, no there's no particular change is there in the elementary Trueman biology edition 2018 and 2019 of class 11th and 12th.

This book is really good for understanding the basics as the theories are given in a very descriptive manner but there is less number of practice sets. This book is not recommended if you want to appear for NEET. But this is a good book for understanding the concepts.

So there's no change in the editions. 

Hope it helps. All the very best for your future endeavours.

For any further queries please feel free to ask.