JWs do not believe Jesus is an angel now. This understanding goes back as far as pre-1900 Russell. Upon resurrection, Jesus was given the "divine quality" and became "immortal and incorruptible", have life within himself - self-generating, requiring no external needs. Essentially what Jehovah God is. He assumed the office, function and role as Michael the archangel but he has not the nature of an angel, as angels can be destroyed, whereas Jesus cannot.
*** w63 12/1 pp. 733-734 The Gift of Immortality ***
Although they will enjoy human perfection, they will still be corruptible because they will still be made of flesh that is capable of decaying or of being destroyed by another creature. They will have the power to live indefinitely, but for them to continue living they will have to keep their bodies supplied with food and water. Without these necessities they would waste away. Such is not the case with the few who are made incorruptible by being given the gift of immortality. Their continued existence is not dependent upon outside sources of energy. God has given them the power to be self-sustaining, just as he is. . . The angels have the power of an indefinite life, but their life force is not self-sustaining and indestructible. Immortality was never given to them. This is evident from the fact that the resurrected Jesus was the only one of Jehovah’s creatures who possessed it in the days of the apostle Paul, although angels had been living for a very long time before then.
*** w69 12/1 p. 735 Questions from Readers ***
The exalted Jesus Christ and the anointed Christians resurrected to rule in heaven with him are actually on a higher level than the spirit creatures normally called angels. Jesus and his anointed followers in heaven are immortal. (1 Tim. 6:15, 16; 1 Cor. 15:51-54) In contrast, the angels are mortal, as can be seen from the fact that Satan and his disobedient angels will be destroyed. (Rev. 20:10, 14; Luke 8:30, 31) Additionally, the Bible shows that Christ has been elevated above the angels and that his anointed followers will share in judging angels.—Heb. 1:4; Phil. 2:9-11; 1 Cor. 6:3.
Nonetheless, Jesus after his resurrection is still called Michael the archangel. (Jude 9; Rev. 12:7) And it appears that the exalted Jesus is referred to as an angel in Revelation 20:1 for, as God’s king, he is the logical one to bind Satan and the demons. So evidently, the term "angel" as designating an office may be used in a general sense to refer to all heavenly spirit creatures.