yes, I think this issue has to be solved. The author of the issue is right.

Make Kyiv, not Kiev...

copy-paste from the timezone datebase:

# From Paul Eggert (2018-10-03):
# As is usual in tzdb, Ukrainian zones use the most common English spellings.
# For example, tzdb uses Europe/Kiev, as "Kiev" is the most common spelling in
# English for Ukraine's capital, even though it is certainly wrong as a
# transliteration of the Ukrainian "Київ".  This is similar to tzdb's use of
# Europe/Prague, which is certainly wrong as a transliteration of the Czech
# "Praha".  ("Kiev" came from old Slavic via Russian to English, and "Prague"
# came from old Slavic via French to English, so the two cases have something
# in common.)  Admittedly English-language spelling of Ukrainian names is
# controversial, and some day "Kyiv" may become substantially more popular in
# English; in the meantime, stick with the traditional English "Kiev" as that
# means less disruption for our users.

If the timezone database changes the name joomla will follow this in the meantime we will not confuse our users and introduce a mapping layer between joomla and php.

So if you want to change it please suggest the change to IANA

Confirmed. It comes from the IANA time zone database. You can find their discussions about this issue in their mailing list http://mm.icann.org/pipermail/tz/. I was following that in past because I had to deal with timezones for other purposes than Joomla. See e.g. this thread in their mailing list: https://mm.icann.org/pipermail/tz/2017-December/025690.html. And there was much more.