It's a great step by step of the process needed to modernize a legacy application.
In addition to what Michael said, watch out for terminology like domain models. Depending on the audience you may need more time to explain domain models (without going into ubiquitous language) or avoid it all together.
Excellent talk! I think it would benefit from some more explanations of the "whys", though.
A developer already experienced in refactoring and modernizing legacy application knows why one would want to take advantage of autoloading, adherence to the PSRs, dependency injection, and so forth. One who does not have such experience, however, may understand what should be done and how, but may not know the reasoning behind it. Preceding the examples with a brief "autoloading is better than include/require, and here's why" or "PSR-4 is better than Foo_Bar_Baz, and here's why" would not take very much extra time and would likely help less experienced developers get more out of the talk.
As-is, the talk is very suitable for an intermediate or advanced audience. Great job!
Excellent talk! Well structured with plenty of examples and easy to follow.