Thanks for all replies but.. situation is still unconfirmed.
@jobeard you're telling about TOR, tracking... maybe an example :
An jurnalist uses the same DWR-118 ROUTER (with USB port) like this
(http://www.dlink.com/gr/el/products/dwr-116-wireless-n300-multi-wan-router ) with 2 different 4g USB modems like this:
https://www.4gltemall.com/huawei-e3372-4g-lte-cat4-usb-stick.html
He uses 4g modems with ANONYMOUSE SIM CARDs from mobile Internet Provider like O2 or VERIZON in UK.
1st 4g usb modem jurnalist uses to own facebook (he uses only at home)
2nd 4g usb modem jurnalist uses to contact with people whose give information to articles (he uses this configuration outside home for security purposes - geolocation)
Jurnalist wants to know if someone could link 1st modem with 2nd modem based on ROUTER metatags (like MAC address, serial numbers, other which he dont know)
Does anyone know answer for this question and could give few arguments for it?

. If any s/n, MAC address, any others device identification numbers will be sent to Mobile Internet Provider?
Well, reading the data sheet tells you it's a Mobile Hotspot, driverless and managed with a web interface (so you need an ISP connection to even access it and 'disable all lan/wifi cards' will not work).
It will work. I have a PC without WIFI and lan cards. I can put 4g usb modem to PC USB port, install software attached to 4g usb modem and make mobile Internet Connection.