Finally, something right up my alley being that I'm Hebrew.
If a foreigner in the United States obeys the laws of a country, does that automatically make that foreigner a United States citizen? No. But while the foreigner is in the U.S., that person is obligated to observe the laws of this land, citizen, native, or otherwise.
While some might think this is just splitting hairs, it is important to note that Jews do not use the term Law Covenant or Mosaic Law Covenant like the Jehovah's Witnesses. Why not? Because it is not a covenant involving a law. It's a covenant that involves a people, the Jews, and the author or the covenant, HaShem (God). Torah, what Gentiles and Christians often call the Mosaic Law, makes up the constitution of the covenant. Since the two parties (the children of Abraham and HaShem) made the covenant at the foot of Sinai, it is referred to as the Sinai Covenant.
For the Jehovah's Witnesses--who approach religion like a scholastic or academic exercise--it's all about rule-keeping and words, so of course they concentrate on who obeys the laws. But the covenant is not with the foreigner who was in the midst of the children of Abraham at the time HaShem made the Hebrews a nation all his own. The laws themselves show this to be so, for while the Jews were told to displace the foreigners who lived in the land promised to Abraham and his children, they were also warned to avoid mistreating the foreigners who were already in their midst.
The Hebrew word translated as "alien resident" in the New World Translation is translated in English as "foreigner" or "non-Jew" in Jewish texts. Since the text in Ezekiel refers to the "foreigners" receiving a share among Israel at the time of the Messiah, they could not have been included in the Sinai Covenant. The text in Ezekiel speaks of non-Jews who have 'given birth to children living among you,' speaking of the foreigners who went into the Promised Land with the Israelites under Joshua. If they were already included in the promise, then Ezekiel would not have spoken of a future time (which is why Christians interpret this text as applying to them now under Christ, not something that was possible before Jesus).
Neither Jewish tradition or history or the way Jews read, translate or interpret Scripture leave room for any doubt: the "alien residents" were "non-Jews" and thus not included in the Covenant of Sinai. It it thus incorrect to speak of these non-Jews as 'second-class Israelites' since they were never Isrealites of any type to begin with and thus could never be beneficiaries.