The same problem after upgrading openssl:

-bash-4.3# service mysqld start
Adjusting environment for mysqld:                                                                                                                                                                                                                                    [ DONE ]
Starting mysqld service: 2019-03-25T15:53:39.135308Z 0 [Warning] [MY-011070] [Server] 'Disabling symbolic links using --skip-symbolic-links (or equivalent) is the default. Consider not using this option as it' is deprecated and will be removed in a future release.
2019-03-25T15:53:39.137123Z 0 [System] [MY-010116] [Server] /usr/sbin/mysqld (mysqld 8.0.15-alt1) starting as process 1136
2019-03-25T15:53:39.138863Z 0 [Warning] [MY-013242] [Server] --character-set-server: 'utf8' is currently an alias for the character set UTF8MB3, but will be an alias for UTF8MB4 in a future release. Please consider using UTF8MB4 in order to be unambiguous.
2019-03-25T15:53:39.138879Z 0 [Warning] [MY-013244] [Server] --collation-server: 'utf8_general_ci' is a collation of the deprecated character set UTF8MB3. Please consider using UTF8MB4 with an appropriate collation instead.
2019-03-25T15:53:39.142767Z 0 [Warning] [MY-010068] [Server] CA certificate /var/lib/mysql/ca.pem is self signed.
2019-03-25T15:53:39.165561Z 0 [Warning] [MY-013245] [Server] The SSL library function CRYPTO_set_mem_functions failed. This is typically caused by the SSL library already being used. As a result the SSL memory allocation will not be instrumented.
2019-03-25T15:53:39.169391Z 1 [ERROR] [MY-011011] [Server] Failed to find valid data directory.
2019-03-25T15:53:39.173416Z 0 [ERROR] [MY-010020] [Server] Data Dictionary initialization failed.
2019-03-25T15:53:39.173630Z 0 [ERROR] [MY-010946] [Server] Failed to start mysqld daemon. Check mysqld error log.
2019-03-25T15:53:39.173570Z 0 [ERROR] [MY-010119] [Server] Aborting
2019-03-25T15:53:39.188598Z 0 [System] [MY-010910] [Server] /usr/sbin/mysqld: Shutdown complete (mysqld 8.0.15-alt1)  (ALT Sisyphus).
                                                                                                                                                                                                                                                                     [FAILED]
-bash-4.3# rpm -qa '*ssl*'
libssl10-1.0.2r-alt2.x86_64
libssl-devel-1.1.1b-alt1.x86_64
libssl1.1-1.1.1b-alt1.x86_64
python-module-backports.ssl_match_hostname-3.5.0.1-alt1.1.x86_64
docbook-style-dsssl-1.79-alt3.noarch
python-module-passlib-1.7.1-alt1.noarch
openssl-1.1.1b-alt1.x86_64
-bash-4.3#

Can't reproduce on systemd virtual machine: neither systemd unit nor SysVInit script fail to start.
There are similar warnings in the log file but server stays operational for both upgrade and new installation usecase.
I'll try to analyse warning sources.

Was it a brand new installation or an upgrade?
Do you use SysVinit machine?

(In reply to comment #2)

> Was it a brand new installation or an upgrade?

It was a new installation after mariadb. It replaced mariadb.

> Do you use SysVinit machine?

Yes.

Probably, the error is:

2019-03-25T15:53:39.169391Z 1 [ERROR] [MY-011011] [Server] Failed to find valid data directory.

It is specified by the datadir config parameter.

Probably, it is missing after installation of the package.

(В ответ на комментарий №4)
> Probably, the error is:
> 
> 2019-03-25T15:53:39.169391Z 1 [ERROR] [MY-011011] [Server] Failed to find valid
> data directory.
> 
> It is specified by the datadir config parameter.
> 
> Probably, it is missing after installation of the package.

In my case, when installing MySQL instead of previously installed MariaDB, I get the following(for systemd machine):

2019-03-26T15:21:10.981325Z 1 [ERROR] [MY-012530] [InnoDB] Unknown redo log format (103). Please follow the instructions at http://dev.mysql.com/doc/refman/8.0/en/ upgrading-downgrading.html.
2019-03-26T15:21:10.981349Z 1 [ERROR] [MY-012930] [InnoDB] Plugin initialization aborted with error Generic error.
2019-03-26T15:21:11.582280Z 1 [ERROR] [MY-011013] [Server] Failed to initialize DD Storage Engine.
2019-03-26T15:21:11.582590Z 0 [ERROR] [MY-010020] [Server] Data Dictionary initialization failed.
2019-03-26T15:21:11.582865Z 0 [ERROR] [MY-010119] [Server] Aborting

And something like yours logs for SysV.

I guess the bug name should be changed to something like "Data directory/format problems after drop in replacement of MariaDB by MySQL"
All SSL issues mentioned in logs are warnings.

Что вы мучаетесь ? Современный MySQL не является 100% заменой современной MariaDB. Гарантированно работающая миграция возможна только через полный дамп содержимого базы и импорт.