For speculation about locations, particularly countries visited, I'm going to look at the last 10 seasons (20-29).
There were 8 new countries visited during this period (Paraguay, Azerbaijan, Malta, Monaco, Zimbabwe, Colombia, Armenia, & Georgia); although not technically countries themselves, French Polynesia, Northern Ireland, and Wales could be included in this list. That averages out to about 1 new country per season, so I predict one new country to be visited in Season 30. As for that, let's look at other countries first.
So I looked at each country visited in each season, including French Polynesia, Northern Ireland, & Wales (but not the US Virgin Islands, as it is a territory of the host country - the United States). I produced the following list. Note that the number next to each country is the number of times the country had been visited before each respective season. The number next to each season number is each of its countries added up. I'm going to call the number next to each season number it's "score."
Twenty One (27)
Twenty Two (23)
French Polynesia (0)
New Zealand (3)
Northern Ireland (0)
Twenty Three (21)
United Arab Emirates (2)
Twenty Four (31)
Sri Lanka (1)
Twenty Five (22)
Twenty Six (31)
Twenty Seven (45)
Twenty Eight (33)
United Arab Emirates (3)
Twenty Nine (27)
South Korea (2)
The average score is 28.9, so I'm going to reasonably assume Season Thirty will have a score of 29. So how will it get to 29? Well, it depends on the countries visited. Of the last ten seasons, all but one visited either 8 or 9 foreign countries, with Season Twenty Two visiting 10. Let's be liberal and say that Season Thirty will visit nine foreign countries. If just two of those are China and India, then Season Thirty will already have a score of 24! Unless the remaining countries have only been visited once before or not at all, then the score will overshoot our goal of 29.
So, let's talk about continents. As I ❤️ TAR mentioned, South America will probably be skipped, as it has been visited in each of the last four seasons. Seasons Twenty Eight and Twenty Nine both visited North America, both Spanish-Speaking countries (Mexico and Panama, respectively). As such I believe Season Thirty will skip North America UNLESS it is an English speaking country like Belize, Canada, the Bahamas, or a small Caribbean island. But I personally believe this chance is small. As for Africa, I personally do not think it will be visited. It has been visited in six of the last ten seasons. It's a true toss up honestly, but I personally think it will be skipped.
With this, I can predict a visit to Oceania, Asia, and Europe, probably in that order too. If Season Thirty starts off with two legs in Australia (as everyone - including me - is predicting), it will start out with a score of 4. So, legs 3-11 will have a combined score of 25, with 7 or 8 countries left to visit. Let's just divide up the remaining 9 legs between Asia and Europe for all intents and purposes, and say that legs 3-6 are in Asia and 7-11 are in Europe. Where will legs 3, 4, 5, & 6 going to take place? I'd say safe guessed are countries with scores of 0, 1, 2, and 3 are as follows:
Asian Countries with Scores of 0:
Asian Countries with Scores of 1:
Asian Countries with Scores of 2:
Asian Countries with Scores of 3:
Now of course South Korea and the Caucasus are out. I'd reasonably assume Philippines, Brunei or Laos, and Singapore to take up legs 3-5 or 6, with leg 6 or possibly 7 in the Middle East or one of the Stans.
Now if legs 1-6 follow as stated, we have achieved a score of between 10-15. With legs 7-11 in Europe, we have roughly 14-19 points to go to achieve our goal of 29. This will be pretty easy, especially considering that every winter season since Season Fourteen has visited a Germanic country in Central Europe. If we say leg 7 is in Germany, that adds 9 points to our score! This is okay, as there are several unvisited countries in Europe. Let's analyze Europe as we just did with Asia:
European countries with a score of 0:
Bosnia & Herzegovina
European countries with a score of 1:
European countries with a score of 2:
European countries with a score of 3:
I'd say that, especially with a leg or two in countries with a high score like Germany, France, or Italy, 3 or 4 legs could be located in countries with scores of one or zero!
As for the finale. Correct me if I'm wrong, but the there have only been three times the finale had teams fly from Europe to the West Coast (Seasons Thirteen, Fifteen, and Twenty Four). I'd say a finale in Seattle or California is inviting, especially since these three seasons ended in Portland (13) and Las Vegas (15 & 24).
Thus concludes my analysis. Enjoy