No, Hebrews is understandable with the first being taken away because the Abrahamic covenant is a covenant of promise. The "first" is defined within the text and there's no need to speak of God's covnant with Abraham as the promises remain in tact. No where are these limited as the only covenants God has made, so it is perfectly acceptable when comparing one to the other to speak of the Sinai covenant as "the first."
I think the issue deals with time. Which aspect of salvation are we abiding in at the time. When we are first saved initially, it is by God’s grace without any works of any kind because we are being initially saved by God’s grace (Believing the gospel in 1 Corinthians 15:1-4 in that Jesus died for our sins, He was buried, and He was risen three days later, calling upon the name of the Lord Jesus (Romans 10:13), which implies seeking forgiveness with the Lord, and receiving Christ (John 1:12). If a believer stumbles into sin on rare occasion, they go to God’s grace by confessing their sins to Jesus (1 John 2:1, 1 John 1:9, Hebrews 4:16) so as to be forgiven of sin. A believer does not do a good work to absolve sin. Thus… grace is the entrance gate and foundation upon which we stand. This lines up with Ephesians 2:8-9, Romans 4:3-5, Titus 3:5.
But after we are saved by God’s grace, there is a secondary aspect of salvation we need to enter into. This is the Sanctification Process by the Spirit (to live a holy life). This is the evidence or proof that God lives inside of us (Who is the source of our salvation). God works in our lives and He molds and shapes us to do His will. For God commands us to be ye holy as He is holy. For without holiness, no man shall see the Lord (Hebrews 12:14). The gospel is 1 Corinthians 15:1-4. Nothing more, and nothing less. But there is also a CALL of the gospel according to 2 Thessalonians 2:14 (Not that it is the gospel). This call of the gospel is defined for us in verse 13 in that… God has chosen us to salvation through Sanctification of the Spirit and a belief of the truth (2 Thessalonians 2:13). This lines up with what James says in that faith (belief) without works is dead (James 2:17). This lines up with what James when he said we are justified by works and not by faith alone (James 2:24). But faith (belief) also justifies. For we are first saved by Jesus Christ by a belief in Him as our Savior. We did not jump through a bunch of hoops to get saved. We were saved solely by God’s grace and mercy when we first came to the Lord Jesus. Sanctification cannot be the entrance gate or foundation of our salvation. It can only follow after we are saved by God’s grace. For if holy living was the basis of my salvation I would be doomed because my past life of sin needs to be wiped out. Only God’s grace can deal with such a thing. For nobody can be saved by having their good deeds outweighing their bad deeds. Salvation is not on the basis of works alone. Salvation is based upon God’s grace. Without that, we got nothing.