Texas law says that a will has to be probated within four years. This rule is found in Texas Estates Code § 256.003:
… a will may not be admitted to probate after the fourth anniversary of the testator’s death unless it is shown by proof that the applicant for the probate of the will was not in default in failing to present the will for probate on or before the fourth anniversary of the testator’s death.
The will can be probated after this four year period. The courts will usually want some testimony or proof that the applicant was not in default in failing to present the will for probate within four years. This usually requires an explanation that the applicant did not know that probate was needed, that the will existed, etc.
The four year rule noted above is the general rule for when the will has to be probated. It does not mean that the person who has the original will can simply do nothing for four years.
It also does not mean the person who has the original will can keep the will secret for four years.
The person who has the original will is required to deliver the will with the clerk. This requirement is found in Texas Estates Code § 252.201. This rule is not tied to the four year period to probate the will. Delivering the will and probating the will are two entirely separate concepts.