Is Islam an "Upgrade" of Christianity?

1) Reassembling earlier Abrahamic stories, and its doctrinal limits

Few new truths, and heavy borrowing from Jewish and Christian traditions
Islam presents itself as the "final revelation," the "last prophet," the "complete edition."
It sets Muhammad up as the final prophet and claims to have corrected and completed the earlier revelations of Judaism and Christianity.

But something's odd.

It introduced few truly new truths.
The framework of absolute monotheism, law and norms, fasting and prayer had already existed in Judaism for a very long time.
Judaism is centered on one God, a life shaped by scripture and tradition, and a legal order.
Christianity, too, already had God, revelation, judgment, prayer, fasting, almsgiving and the idea of a Messiah.
Islam, in this view, was layered on top of an already existing Abrahamic tradition.

2) Removing a core doctrine and simplifying practice

Deleting Jesus's divinity and turning older traditions into a manual
Deletion stands out more than addition.
Christianity sees Jesus as the Son of God and divine; Islam honors Jesus as an important prophet but denies His divinity.

The practices existed before too.
Islam's Five Pillars, the profession of faith, prayer five times a day, almsgiving, fasting during Ramadan and pilgrimage to Mecca, are a very clear and strong system of practice. But rather than an entirely new product, they're closer to a simpler, unified packaging of the prayer, fasting, charity and pilgrimage traditions already found in the Jewish and Christian worlds.
Less "new doctrine" than "a simplified, re-edited user manual."

3) Claiming to be the final edition by modifying the original

No new insight, more like a simplified, backward-compatible version
Upgrade or benchmarking?
An upgrade usually means new insight, deeper explanation and richer truth. In Islam's case, it looks more like a simplified version.

Judaism and Christianity, which first established and developed the whole biblical tradition, are closer to the original. Islam appeared later and reassembled those materials, yet calls itself the final edition.

Conclusion: the claim of final revelation vs. the reality of violence

Religious persecution reported by the international community
An "upgraded" religion that kidnaps?
International human rights groups and news reports continue to document rising violence and persecution against Christians by Islamist militants. Nigeria in particular has been reported as one of the deadliest countries in the world for Christians.
Attacks by jihadist groups, including Islamic State affiliates, keep coming, with churches and villages suffering heavy losses, and mass kidnappings of students continue to be reported.
All because people don't follow what these militants claim is the latest, upgraded faith.