No, they can't simply just contact your registrar and get it back. They must file a UDRP with WIPO. And it costs $$$. Filing a UDRP with Czech's arbitration court used to be the cheapest alternative (~USD$550 [500 euros]) but they've increased their fees (maybe because of too much demand as many know it is the cheapest way to file a UDRP

). Read it here:
http://www.circleid.com/posts/20180111_new_udrp_filing_fees_at_czech_arbitration_court/
If you're registering domain names with generic keywords, you don't have to worry about it. As long as it is not some company names (e.g: Estee Lauder, Gucci, Microsoft, Facebook, .etc.).
However, there are numerous cases of companies filing UDRP against individuals for generic keyword domain names. But if you or your lawyer knows how to defend it, you can win. There had been cases of this. For
example:
http://www.wipo.int/amc/en/domains/search/text.jsp?case=D2016-1048
Your chance of losing the case increases whenever you fulfil any of these 3 conditions:
- Identical or Confusingly Similar
- Rights or Legitimate Interests
- Registered and Used in Bad Faith
For example, you register EsteLauder.com or Guccii.com or have a similar sounding domain name and you've set up a website with an identical logo like the complainant's; parking the domain name and not using it (no legitimate interest) OR don't have a proper trademark for it (only worry about this if a company owns a trademark brings this point up); or registering the domain name and redirecting to related offers (e.g: a golf company's trademark and you redirect visitors visiting it to golf related products - it qualifies as using it in bad faith), trying to sell it back to the former owners or company who owns the trademark for any amount of money. For the last point, what makes Mickyfu's case different is because he registered the domain name before the trademark was filed. So he may have a chance to win, especially since there's a change in internet laws (that is why every outcome of lawsuits or cases will be used for future lawsuits - lawyers citing them, and so on). If you've read the above WIPO case (in fact, any lawsuits and cases), you will see how lawyers love citing and referencing archived cases.
As long as you do not fulfil the 3 conditions as stated above, your chance of winning the case is pretty secured.
Actually, there are a lot more I can dwell on. But as long as you don't fulfil that 3 conditions above (and don't register any company's trademarks), you're pretty safe.
Anyway, here's a good read:
https://www.domainsherpa.com/generic-investing/
But yeah, don't worry about it. And say, if you DO get a UDRP, you can do what most defendants do - ignore it. Then when WIPO decides in favour of the complainant, your registrar will automatically just transfer the domain name over to the complainant. You may pay a small penalty fee though. And I believe you could get banned if you get too many UDRP complaints and lost it (as it is usually against the domain registrar's TOS - infringing trademarks). Also, just look at the concluded outcomes of UDRP cases (
http://www.wipo.int/newsletters-archive/en/domain_names.html) - notice how few there are - just one every several days!
Good luck!