How unsafe is the use of sun.misc.Unsafe actually?

I am wondering about how unsafe the use sun.misc.Unsafe actually is. I want to create a proxy of an object where I intercept every method call (but the one to Object.finalize for performance considerations). For this purpose, I googled a litle bit and came up with the following code snippet:

class MyClass {
  private final String value;
  MyClass() {
    this.value = "called";
  }
  public void print() {
    System.out.println(value);
  }
}

@org.junit.Test
public void testConstructorTrespassing() throws Exception {
  @SuppressWarnings("unchecked")
  Constructor<MyClass> constructor = ReflectionFactory.getReflectionFactory()
      .newConstructorForSerialization(MyClass.class, Object.class.getConstructor());
  constructor.setAccessible(true);
  assertNull(constructor.newInstance().print());
}

My consideration is:

• Even though Java is advertised as Write once, run everywhere my reality as a developer looks rather like Write once, run once in a controllable customer's run time environment
• sun.misc.Unsafe is considered to become part of the public API in Java 9
• Many non-Oracle VMs also offer sun.misc.Unsafe since - I guess - there are quite some libraries already use it. This also makes the class unlikely to disappear
• I am never going to run the application on Android, so this does not matter for me.
• How many people are actually using non-Oracle VMs anyways?

I am still wondering: Are there other reasons why I should not use sun.misc.Unsafe I did not think of? If you google this questions, people rather answer an unspecified because its not safe but I do not really feel it is besides of the (very unlikely) possibility that the method will one day disappear form the Oracle VM.

I actually need to create an object without calling a constructor to overcome Java's type system. I am not considering sun.misc.Unsafe for performance reasons.

Additional information: I am using ReflectionFactory in the example for convenience which delegates to Unsafe eventually. I know about libraries like objenesis but looking at the code I found out that they basically do something similar but check for other ways when using Java versions which would not work for me anyways so I guess writing four lines is worth saving a dependency.