In the US, the requirements are specified in FAA Order 8260.3, United States Standard for Terminal Instrument Procedures (TERPS).
Section 2-3 states:
2-3. General PA Requirements. See Order 8260.19 for requirements
related to GPA/TCH coincidence.
a. GPA. Utilize a standard 3-degree
GPA where possible. GPAs greater than 3 degrees but not more than the
maximum (table 2-1) are authorized without approval when needed to
provide obstacle clearance or to meet simultaneous parallel approach
standards. Other cases or GPAs less than 3 degrees require Flight
Standards or military authority approval (USAF not applicable).
b. TCH. The published TCH (nearest whole foot) should accommodate the
largest aircraft height group normally expected to use the runway and
must not be less than the minimum or exceed the maximum TCH. Note:
60 feet is the maximum TCH regardless of height group.
(1) CAT I.
The TCH is based on achieving an acceptable wheel crossing height
(WCH). The WCH is the difference between the TCH and the approximate
glidepath antenna-to-wheel height (see table 2-2).
(a) The optimum
TCH provides a 30-foot WCH. It must provide a WCH no less than 20 feet
or greater than 50 feet.
(b) Displaced Threshold Considerations. The
TCH over a displaced threshold can result in a WCH of not less than 10
feet if the height of the glide path over the beginning of the full
strength runway pavement suitable for landing falls within the
minimum/maximum TCH values.
(2) CAT II/III. The optimum TCH is 55
feet and must be between 50 and 60 feet regardless of height group.
Note: To determine the
minimum allowable TCH, add 20 feet to the glidepath-to-wheel height
and to determine the maximum allowable TCH, add 50 feet to the
glidepath-to-wheel height (not to exceed 60 feet).
So, the answer to the question is ; No, they are not all 3 degrees and 50 feet.