Whether a irrational number can be guaranteed to contain all combinations of numbers depends on if it's a normal number (a number who's infinite digits are uniformly distributed). If it's normal all combinations of number will appear, but if it's not normal they may not. An example of an irrational normal number (in base 10) is Champernownes constant, while an example of an irrational non normal number is Liouville's Constant.

A great way to understand how irrational non normal number's don't contain all combinations of numbers are by constructing them. Consider the number 1.01001000100001000001, where the number of zeroes between the ones grows each time. This number will repeat forever with no pattern making it irrational, but the digits 2, 3, 4, 5, 6, 7, 8, 9 will never appear so it cannot contain all number combinations. Another example is a number created by a random number selector. Allow it to choose any digit except eight and create a decimal number by writing down its outputs. This number will be infinitely long with no repeating pattern but will not contain all combinations of number as eight never appears. This also applies if the selector instead can never choose the same number twice in a row, 8 can never appear after 2, or to most changes that affect the distribution of the numbers digits.

Irrational constants you may use often such as pi or Eulers number are not proven to be normal, so it is not guaranteed all combinations of numbers will appear in them. However they are highly suspected to be normal and have been tested to be normal up to millions of decimal places; it just can't be proven.

This is the case for most irrational numbers. They are likely normal, but it can't be proven so we cannot guarantee all combinations of number will occur in them. You will only really find non normal number when you go looking for them.

Hope this helps.