Proguard removes method invocation, changing behaviour about proguard HOT 1 OPEN

Simple example:

public interface MyConsumer<T> {
    public void accept(T t);
}

public class Test {
	public static void main(String[] args) {
		MyConsumer<String> c = consumer();
		c.accept("Hello, World");
	}
	
	private static MyConsumer<String> consumer() {
		return Test::println;
	}
	
	private static void println(String message) {
		System.out.println(message);
	}
}

After some testing, it is indeed seems like Proguard assumes that invocation of MyConsumer::accept has no side effects if there are no implementations of it in the jar file. If I add at least 1 file that references MyConsumer and use it in the code issue disappears.

Small sample, change .zip to .jar
For the sake of simplicity, use Java 8. Jar doesn't include logic necessary to run on newer versions.
Proguard settings:
Shrinking enabled, Test::main is kept
Obfuscation disabled
Optimizations enabled, 5 passes, all boxes under 'Remove' and 'Remove debugging' are unchecked
dontwarn is set to 'java.lang.invoke.**'

from proguard.