It was a bit harsh from him, but in reality Slovakia barely is a top-10 country. Gap between countries like Denmark/Latvia and Slovakia is smaller than Slovakia and Czech for example. In my opinion:
Canada
USA
Russia
Sweden
Finland
Czech
Switzerland
Germany
Slovakia
Denmark
You are right that gap between Czechs and Slovaks is bigger than between Slovakia and the countries ranked around the 8th place. However saying that Slovakia is not a top 10 nation is stretching it when you look at actual results. The only time we have finished outside of top 10 in the last decade was in 2017 when there was an off ice battle in Slovak hockey and players were on strike and we had a very questionable coach (with all respect to his work with kids) and then you have to go all the way back to the 2010 IHWC when we finished 12th.
Slovakia has been in the top 10 in all IHWC categories over the past decade. Sure, we can have an off year when we get relegated like the u18 team did, but we can also have a good year where we finish 5th.
We are currently lacking in top end talent, but we have a number of decent prospects who if they don't make it in the NHL, could make it in top European league. At least for now and for the next few years, we definitely have a depth advantage over Denmark who struggle without their top players.
Slovakia in the IHWC in the last decade:
2019 9th
2018 9th
2017 14th
2016 9th
2015 9th
2014 9th
2013 8th
2012 2nd
2011 10th
2010 12th
Slovakia at the WJC in last decade:
2019 8th
2018 7th
2017 8th
2016 7th
2015 3rd
2014 8th
2013 8th
2012 6th
2011 8th
2010 8th
Slovakia at the u18 WC in last decade:
2019 10th
2018 7th
2017 6th
2016 5th
2015 7th
2014 8th
2013 9th
2012 11th
2011 10th
2010 8th