Early in my practice (Mahasi noting), I had plenty of thoughts come up to note, as taught, but lately there is only the meditation object. Is this normal or just another impermanent thing that will change with changing experience? I have meditated 5-6 months, and the last two I've had this (disappearance of outside thought) so to speak. Thanks.
From what you have said, it seems that you have developed meditation to a degree that you can come to Ekaggata with ease. You seem to have the ability to keep the mind on one object. By going beyond the first jhana you will get to experience piti (joy), sukha (body lightness), and ekaggata (one-pointedness). In the second jhana, both vitakka and vicara are absent.
But you should exercise caution if you’re trying to go beyond the fourth jhana. I do hope that you are fully grounded in Dhamma if you are to on this route. If you are not established on a good firm foundation in Dhamma, you are asking for trouble, as you will then come to the “Asanna realm”.
Sanna is, at the very fundamental level, the recognition of an external stimulus. Without sanna we cannot identify things around us, and also cannot communicate with each other meaningfully. But beings have no sanna or perception in the “Asanna realm”. Those beings are without any awareness. Nothing registers in the mind. If someone gets to the “Nevasanna Na’sanna“ realm without being fully established in the path, then that person will have difficulty in coming out of this Asanna realm.