I think SAP is about to start getting replaced on a regular basis for a few reasons.
Their software is dog old. Ancient ABAP stuff from the 70s that has been hated by users since the 70s.
Their cloud story is a mess. They have all these random acquisitions which they are trying to squeeze in somewhere (ironically exactly what they used to make much of Oracle doing). They have their IaaS partnerships. They have the useless HEC cloud... A mess.
HANA is a complete money grab and the opposite of what people want in software. Everyone else is going SaaS where the software company includes and manages the database (even Oracle, the database company). SAP decided that people want to pay millions upon millions to flip out a mature database with an immature database and then manage it.
No one wants multi year, multi million dollar software upgrade projects in the SaaS era. That is ridic.
People no longer think you need to buy all your Enterprise software from one company, which was always how SAP won... their integrated story. People would rather have best of breed.