Notes should be taken with a grain of salt as it's just notes I took during the livestream and since I'm no contributor to forge I cannot attest to the accuracy of facts.
- cpw is rewriting the mod loader and it's going to be merged into 1.13 forge
- 1.13 forge will have java 9 support. (May happen sooner rather than later)
- The mod loader carries a lot of technical debt, which is the reason the load speed is a bit slow, they're working towards improving the performance of the loader.
- Java 10 & 11 support depends on Mojang using it. Go yell at them for support.
- Forge will receive a full audit for 1.13, going over all of the classes for redundancies. Stable 1.13 Forge might take months.
- New coremod system for 1.13, coremods are necessary for forge, but people tend to overuse them right now.