Earnest said:
"The Watchtower article with which you disagree indicates it is referring to God's name, but it has nothing to do with translation. However, since vs 15 talks about offering God a sacrifice of praise, and vs 16 says that God is well-pleased with such sacrifices, it is quite reasonable to conclude that the sacrifice is made 'to [God's] name."
Absolutely correct. The Pulpit Commentary observes that the author of Hebrews [Traditionally believed to be Paul] uses a phrase that designates the "voluntary peace offering" under the Law. Those offerings were made to Jehovah/Yahweh. The phrase is also used of voluntary thank-offerings. [M. R. Vincent: Word Studies]. So Paul suggests that "confessing his name" is praise made to and about Jehovah the one to whom sacrifices are made. Our praise replaces the animal sacrifices of the Old Law. But the sacrifice continues to be made to God.
Simple grammar verifies that God is meant. To whom does the possessive pronoun "his" [αὐτοῦ] refer? We must refer it to its immediate antecedent, God.