See comment https://github.com/pandas-dev/pandas/pull/17954#discussion_r147298282 and https://github.com/pandas-dev/pandas/pull/17728#discussion_r144095969 about suggestions to make the implementation of concat_same_type cleaner.
Comment From: jbrockmendel
Block.concat_same_type is gone, is this closeable/updateable?
Comment From: jorisvandenbossche
Yes, this can indeed be closed I think. The referenced comments are now also outdated with the introduction of the get_common_dtype interface used in the concat code.