No. Most conservative biblical commentators believe that the Book of Hebrews was written to Jewish believers who were being persecuted for their faith in Jesus as Messiah. They were being tempted to abandon their faith in Jesus and go back into Judaism. The writer wrote to encourage them to stay true to their faith in Jesus, focusing on the superiority of Christ to anything in Judaism and warning them of the consequences of apostasy. (Hebrews 3:6;4:14;10:23,35-39-Note emphasis upon holding fast to the faith)
Of course, only true believers would hold fast to the faith (1 John 2:18,19) under severe pressure. False believers would depart from the faith (Mark 4:16,17). The writer of Hebrews, however, was confident that his readers were true believers and would hold fast to the faith (Hebrews 10:39).
The doctrine that believers will receive eternal rewards as a reward for their obedience to Christ in this life is not emphasized in the Book of Hebrews. However, it is taught in many other passages of Scripture (1 Corinthians 3:10-15; 2 Corinthians 5:10; Matthew 19:27-29; Revelation 22:12). Exactly how the believer will enjoy and use his rewards in the Millennial Kingdom is not specified. It seems reasonable to assume that they will be enjoyed and used in the context of the believer ruling with Christ (2 Tim 2:12) in His earthly kingdom.