Unnecessary and very slow update statement in oracle upgrade script !?

**unnecessary update statement in oracle upgrade script**

Hi we want to migrate from Activiti 5.15 to flowable 6.60.
Our tables are stored in an oracle 19 database and some of them are really big, e.g. ACT_HI_VARINST has 600 Mio rows.

In the script flowable.oracle.upgradestep.6010.to.6100.history.sql i see that there is an add cloumn with default value followed by an update of this column to the same default value, and I am wondering if it makes sense?
See:
https://github.com/flowable/flowable-engine/blob/8c476e8834915291bd6d133ecf3528b9b99e6032/modules/flowable-engine/src/main/resources/org/flowable/db/upgrade/flowable.oracle.upgradestep.6010.to.6100.history.sql#L6

The statement `alter table ACT_HI_ACTINST add REV_ INTEGER default 1` is really fast (only a few Milliseconds), buit the update will take several hours. The reason, as far as i undesratnd , is that in the first statement oracle stores only a metadate and does not write all rows.
Is there any special reason why you force the writing of all rows with the `update` statement?

**Expected behavior**
A fast as possible execution of migration db scripts.

**Additional context**
currently we are using activiti 5.15, we want to migrate to flowable 6.60, The database version is Oracle 19.