The LinearAlgebra`MatrixManipulation` package

[Nusc]

The LinearAlgebra`MatrixManipulation` package is now obsolete with the new version of Mathematica.

Say you had an existing script with commands:TakeRows, TakeColumns, AppendColumns, ZeroMatrix, AppendRows (which are also obsolete)
Mathematica says:

AppendColumns, AppendRows, and BlockMatrix are available in the Mathematica kernel functions Join and ArrayFlatten.
TakeRows, TakeColumns, TakeMatrix, and SubMatrix are available in the Mathematica kernel function Take.

The later has four commands which use one now. How do I know if it's performing the same operation?

 

[Nusc]

Where else can I ask about this? The Mathematica forums aren't much help. Too bad it didn't have as much support as Maple.