On amd64 (possibly i386, did not test there, but can't reproduce on arm64) the following output occurs when you attempt to run msfdb reinit:

msfdb reinit

[i] Database already started
[+] Dropping databases 'msf'
[+] Dropping databases 'msf_test'
[+] Dropping database user 'msf'
[+] Deleting configuration file /usr/share/metasploit-framework/config/database.yml
[+] Stopping database
[+] Starting database
[+] Creating database user 'msf'
[+] Creating databases 'msf'
[+] Creating databases 'msf_test'
[+] Creating configuration file '/usr/share/metasploit-framework/config/database.yml'
[+] Creating initial database schema
Traceback (most recent call last):
12: from /usr/lib/ruby/2.7.0/rubygems/core_ext/kernel_require.rb:92:in require' 11: from /usr/lib/ruby/2.7.0/rubygems/core_ext/kernel_require.rb:92:inrequire'
10: from /usr/share/rubygems-integration/all/gems/bundler-2.1.4/lib/bundler/setup.rb:20:in <top (required)>' 9: from /usr/share/rubygems-integration/all/gems/bundler-2.1.4/lib/bundler/ui/shell.rb:88:insilence'
8: from /usr/share/rubygems-integration/all/gems/bundler-2.1.4/lib/bundler/ui/shell.rb:136:in with_level' 7: from /usr/share/rubygems-integration/all/gems/bundler-2.1.4/lib/bundler/setup.rb:20:inblock in <top (required)>'
6: from /usr/share/rubygems-integration/all/gems/bundler-2.1.4/lib/bundler.rb:149:in setup' 5: from /usr/share/rubygems-integration/all/gems/bundler-2.1.4/lib/bundler/runtime.rb:26:insetup'
4: from /usr/share/rubygems-integration/all/gems/bundler-2.1.4/lib/bundler/runtime.rb:26:in map' 3: from /usr/share/rubygems-integration/all/gems/bundler-2.1.4/lib/bundler/spec_set.rb:147:ineach'
2: from /usr/share/rubygems-integration/all/gems/bundler-2.1.4/lib/bundler/spec_set.rb:147:in each' 1: from /usr/share/rubygems-integration/all/gems/bundler-2.1.4/lib/bundler/runtime.rb:31:inblock in setup'
/usr/share/rubygems-integration/all/gems/bundler-2.1.4/lib/bundler/runtime.rb:312:in `check_for_activated_spec!': You have already activated reline 0.1.3, but your Gemfile requires reline 0.1.4. Since reline is a default gem, you can either remove your dependency on it or try updating to a newer version of bundler that supports reline as a default gem. (Gem::LoadError)