I never saw any push-in, but I'm not an authority, all I ever saw was threaded. I have a '75, CB750F and the zerk in the middle of the swingarm was screw-in stock from factory. I purchased a '72 swingarm bolt with zerks on both ends and converted them to US and both of them were screw-in.
If you really need to know for sure do a search for Hondaman in forum members and send him a PM with your question, year and model, he would know for sure!