Asks me to update virtualbox guest addons in the workstation, safe?

Support
1

The following packages will be upgraded:
virtualbox-guest-dkms virtualbox-guest-utils virtualbox-guest-x11

First time I see that being updated, is it safe and open source?

2

Good day,

this isn’t as safety issue, the guest additions are included with Whonix per default, see:

Installing VirtualBox Guest Additions by Default?

Have a nice day,

Ego

3

Thanks! That was useful to know.
I recall they were not open source right?

4

Good day,

as far as I can tell, the guest additions are actually open source and under GPL, quote:

* Copyright (C) 2007 Sun Microsystems, Inc. * * This file is part of VirtualBox Open Source Edition (OSE), as * available from http://www.virtualbox.org. This file is free software; * you can redistribute it and/or modify it under the terms of the GNU * General Public License (GPL) as published by the Free Software * Foundation, in version 2 as it comes in the "COPYING" file of the * VirtualBox OSE distribution. VirtualBox OSE is distributed in the * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind. * * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa * Clara, CA 95054 USA or visit http://www.sun.com if you need * additional information or have any questions.

Have a nice day,

Ego

5

The summary from Re: Finding correct component for Virtual Box / Debian / screen resolution issue is:

Virtualbox ships a BIOS that requires Watcom to compile from real sources,precompiled copy they ship as well is free but is not the preferred form for modification.

More links on that topic are aggregated here:
VirtualBox Integration

When you make the leap to use VirtualBox licensing, there is no need to worry about VirtualBox guest additions licensing.