I would like to point out some 'small' things you may not have noticed in the MySQL 8.0.17 Release Notes. They are small changes compared to things like MVIs, InnoDB cloning, and the like but these are the types of changes that are subtle that may catch you unaware.
1. Host names have grown from 60 to 255 characters. However your SSL/TLS package may not be able to handle the longer names.
2. If you are an old C/C++ programmer, 'C-style &&, ||, and ! operators that are synonyms for the standard SQL AND, OR, and NOT operators, respectively, are deprecated and support for them will be removed in a future MySQL version'.
3. The ZERO fill attribute is being deprecated as is unsigned FLOAT, DOUBLE, and DECIMAL. You can no longer AUTO_INCREMENT FLOAT and DOUBLE columns.
4. The optimizer will rewrite your WHERE foo to WHERE foo != 0 to ensure complete predicates are being used to plan your query.
